hp_slobo.htm: Understanding, Reversing, and Hacking HP Printers

Back to fravia's Reality Cracking section
Slobotron wrote: "It has come to my attention your essay "The Great Printer Scam". As a former HP Engineer i found it quite superficial and misinformative, because the reality about printers is MUCH worse than in your writings" :-(
He added further: "You posed many interesting and still unanswered questions. You also noticed how much is "extremely difficult" to find related infos on the web. Being my mission rationality and research, i took some time to write for you and for your readers a brief essay..."
This essay is indeed an eye opener. High level of reality cracking. That's what reality cracking should be all about. A clear target, real knowledge, cleverly applied, lotta teachings. Print it with your own printer :-) and sip it slowly this evening. You will NOT forget it, nor the many reversing lessons inside it, never.

Understanding, Reversing, and Hacking HP Printers
"Knowledge is power, but i think that first we should learn HOW to learn"
by Slobotron, April 2002

(see also Fravia+'s older essay [g_prscam.htm], June 2000)

Reality Cracking: Understanding, Reversing, and Hacking HP Printers

Author : SLOBOTRON (slobotron@yahoo.com)
Place : Europe
Date : Feb.2002 (published at http://www.searchlores.org in April 2002)

INTRODUCTION :

This essay is designed for researchers to improve and spread their knowledge in a field that is often underestimated and "closed" about details and specifications.
It seems extremely difficult nowadays to find any kind of detailed infos on the subject.
Due to my vast experience in the sector i felt obliged to put on paper some useful hints for seekers, reversers and crackers, hoping that this essay can be for many an eye-opener.
However this doesnt mean that you should expect a full-disclosure approach, at least for now.
Knowledge is power, but i think that first we should learn HOW to learn.
Feel free to contact the author for any additional questions or to reprint/edit/publish this text.

GOAL :

The contents of this essay will give the reader a wider scenario about printing technologies, explaining why some models are "locked", how to customize a printer, refilling techniques, marketing background and how to "hack" a printer.

SECTIONS :

- Understanding the Printing Market
- Understanding Product Development
- Evil Techniques to Enslave Customers
- Inks and Cartridges Explained
- Refilling Explained
- WaterMarks Explained
- Cost-per-Page Explained
- Hacking HP Printers
- Buying the right printer

UNDERSTANDING THE PRINTING MARKET

Printers are the main HP's "cash-cow", they produce an average of 10 billions $ per year and are the most profitable product-line of the company.
HP has "stolen" part of the concept and the technology about ink-jet and laser printing from Xerox in the early 80's.
Since then, the company developed an amazing reputation on manufacturing strong and reliable products expecially with the LaserJet family.
In the 80's HP was a so called "product-focused" company.Unfortunately after the takeover of the old CEO by the new one (Carly Fiorina), HP is now a so called "customer-focused" company.
This is very important and explains why nowadays HP products are often the shadow of the old good ones.
HP's founders were the famous engineers Bill Hewlett and Dave Packard.
They believed in science, technology and in a company made "by engineers for engineers".
After their death the company is now ruled with few exceptions by salesmen, marketers, and bankers.
The last step to obfuscate the identity of this old good company is the claimed evil merge with Compaq which deserves no comments.

We MUST understand first some brief basics regarding the market.
When a product is made it follows this process :

--> Marketing Research --> Market Segmentation --> Product Development --> Advertising / Propaganda

--> Market Segmentation :

Marketing Research tells us that there are mainly 4 different types of customer segments :

--> Home-Users
--> Small Enterprises
--> Enterprises
--> Graphic Designers

Segmenting the customers in more rational groups is fundamental to satisfy
the completely different demands that millions of users request every day.
This led the company to develop different models for each segment of users
in order to dominate the market.
--> Customer's Needs :

--> Home Users --> Cheap prices, "photo"-quality, bundle with poor sw appz.
--> Small Enterprise --> Good cost-per-page ratio, fair price, flexibility, tech-support.
--> Enterprise --> High productivity, backward compatibility, unix/mac support, cost-per-page, worldwide support 24x7 etc.
--> Graphic Designers --> Support for different papers, Pantone, cmyk, productivity, high quality, sw compatibility (autocad etc).
Every customer segment can use different platforms, networks, software, hardware, people, customs, and has a different concept on how much is willing to pay to print.
A successfull company must then design a specific product for each of this groups to match the demand.(--> product segmentation).
--> Product Segmentation :

--> Home Users --> low-end DeskJets, low-grade OfficeJets
--> Small Enterprises --> mid/high end Deskjets, Laserjets and Officejets
--> Enterprises --> high-end Laserjets, Officejets and often Deskjets
--> Graphic Designers --> Plotters, high-end Deskjets, Color Laserjets

Please take care that the product is never meant for create the best technical innovations, but only to match exactly what the customers want, based on the previous market-segmentation.
Note also that sometimes innovation doesnt pay, and while HP made some very strong products (like LaserJet 3 family),others were doomed to fail (like the terrible PaintJet and the ColorPro series).
(more interesting details in the next section)

--> Maximizing Profits :
--> Note that in most cases the huge revenues are NOT coming selling the printers but obviously from selling the HIGH-cost "consumables" such as toners and inks.
THESE are the real "cash-cows", and the printers are just a mirror to attract the customers.
* Read the details in the "Evil Techniques to Enslave Customers" section.

Note for the reader :

As a rational and analytic person, the reader should NEVER be fooled into thinking that a company is led by innovation or love for technology (--> "made by engineers for engineers", "HP Invent", "The HP way", etc.).
People MUST realize once and for all that the one and only company-mission is to SUCK as much money as possible from each of the customer segments and possibly to bankrupt the competitors in order to gain a monopoly-status (HP has 80% of the worldwide laser market by instance).

UNDERSTANDING PRODUCT DEVELOPMENT

HP's Printers are developed and manufactured in many sites around the world.
In Europe we have only the Barcelona Division that makes OfficeJets and Designjets and the Grenoble Division for various stuff related to cartridges.
In US and Singapore they make DeskJets and LaserJets.
--> You can see where your printer has been made from the s/n.
the first 2 letters tag the country, for example --> SG --> Singapore
--> ES --> Espana (Barcelona)
--> FR --> France (Grenoble)

A printer is basically a motorized electronic-embedded device.
To make one you need first an embedded-device development-toolkit.
You can find many toolkits around the globe to make every kind of small or portable devices.The leader in this field is WIND RIVER Technologies (www.windriver.com).
The most successfull product of Windriver is VxWORKS, a real-time OS with powerful tools,IDE, compiler, debugger, simulator etc that runs on Unix and NT.
HP uses VxWorks to make the firmware of almost all the printers and also other products like the famous HP JetDirect Cards.

Each board uses a specific CPU with often custom memory, bus and flash-bios.
(Mostly used are the Motorola CPUs)

--> note that MANY printers do NOT support flash-bios (at least "officially").
Actually only high-end products support flash-bios.
This is done sending to the printer the bios file via raw LPT under DOS or UNIX , via raw TCP/IP or with the stinking HP's Flash Utilities under Windoze or Mac.

--> Unmounting a Printer we can easily see the CPU model, the memory model, and if present the flash-eeprom model (AMD,Intel,Hitachi,ST,etc).
Using expensive (and dangerous) flash-readers is possible (not always) to rip-off the firmware and theoretically (using IDA for instance), dis-assemble the firmware.
Note that most fw are of course encrypted in some way.

To drive the printers internals HP developed many languages since the 80's.
There are 2 segments of languages used by the printer :

--> Internal Languages (PML,EML,VarWare etc) that drive the mechanic, the half-toning, the render etc using small macro-opcodes.
(the REAL machine language).
The latest trend now seems to use the EIFFEL language that claims to speed up a lot the r&d development.
Apart Eiffel, these languages are NOT accessible from a sw driver, nor you can find ANY kind of decent reference on the web, they're kind of "secret" and copyrighted by HP Labs (www.hpl.hp.com).
Only 3rd party developers interested in writing a specific RIP (Raster Image Processor) can have access to the full language data-sheets, paying a huge sum of money and becoming "HP 3rd Party Official Developer". (such as Adobe, AutoDesk etc).
Unfortunately every model has its own set of additional internal opcodes so there's not a common rule to write for example a hacked driver except for very basic tasks.
--> External Languages :

Regarding "external languages" on the web you can find tons of .pdf files with full documentation, also on good bookstores you can find something.
PJL (Printer Job Language) This small scripting language is used only to manage the job session and is very useful.
With just few commands you can tell the printer how many copies to print, which orientation, b/w or color, zoom factor, scaling, resolution etc.
HPGL (HP Graphic Language) This is a vector-only language (--> unable to print rasters), was mainly used in old plotters for mechanical drawings / technical projects / etc, and was the "de facto" standard in every high-end applications.
HPGL2 (HP Graphic Language 2.0) Version 2.0 of the old HPGL, adding full raster support, and a larger set of instructions, used nowadays in all high-end plotters.
Other similar languages were RTL (Raster Transform Language) and CALS, now obsolete but still supported in high-end machines for backward compatibility.
PCL (Printer Common Language) This Language is raster-only, and is used in ALL hp's printers except rare cases.
There are many versions of PCL : PCL, PCL2, PCL3, PCL5 and custom versions (like the infamous PCL5-GUI) mainly made for "windoze-only" deskjets (like the 720c series that used HPPA, a kind of machine-language made by the driver itself to speed up the process and make it incompatible).
About PCLxx programming you'll find tons of documentation everywhere in the web but the problem is that often if not ALWAYS each model has also its own proprietary set of additional commands and specifications that are of course NOT public except for 3rd parties paying lot of money for the dev-kits.

TCL This language is pure TCL (as the TCL/TK under Unix) but has just a reduced set of intructions to drive the printer internals.
It's used mainly for testing and debugging by the R&D and of course you can NOT find any kind of specification on it related to printing.
Even here each printer can have different sets of instructions or special opcodes.

** Using TCL can be useful to write data inside protected memory areas if you know the right memory mapping.
* Read the "Hacking HP Printers" section for more details.
To print a document, even an empty one, the sw driver must :

--> Create a file containing the PJL HEADER.
--> The PJL Header will then tell the printer to switch in a specific supported language using a specific PJL opcode ("@PJL ENTER LANG=<lang>").
--> After this instruction the driver will attach the encoded file.
--> At the end of the file there's the PJL EOF command to terminate the job.
While the majority of these languages are well documented, many others are not , that's why is sometimes impossible to write for example a driver for UNIX (like a simple filter for GhostScript).
Note also that HP gives public just the documented features and commands but often there are undocumented ones that may be VERY important for performance or quality.
(a typical example under unix is the HPPA driver for the 720xx series that sucks compared to original windoze-only made by HP).

** A lot of .pdf files and some poor bad-documented dev-kits can be found in the HP's developer site.
---> http://developer-solutions.hp.com

EVIL TECHNIQUES TO ENSLAVE CUSTOMERS

There are many evil tricks that the marketing can use to suck money from our pockets.
Lets see and reverse the most interesting ones used to enslave the customer on buying only HP recharges, paper, inks, etc.
--> Charging inks at premium price while selling the printer as fair price.
The best way to start enslaving a customer on a specific brand is to make the product cheaper, attractive and bundled with useless software for beginners (light editions of Corel etc) Average home-lusers are unaware of the fact that buying just 3-4 new cartridges they can spend more than an entire new printer loaded with 2 carts, and that he cannot use 3rd party parts or 3rd party drivers or 3rd party papers to achieve good results.
* Epson cartridges are much worse than HP's regarding price, *real* amount of ink and durability.
They also dont mount the printhead on the cartridge.When the printhead is deteriorating you got to change the entire carry for a totally crazy waste of money.
As a result Epson has a very expensive global-cost, even using it as b/w in econo-mode.
* Read the details in the "Inks & Cartridges Explained" and "Refilling Explained" sections.
--> Forcing customers into buying insulting and unwanted features

The majority of home users print mainly text and rarely some photos.
To achieve a good text quality a *real* 300x300 dpi is far enough.
600x600 makes sense only for vector/technical drawings or very complex fonts.
Epson started years ago fooling customers on the equation that "more dpi=more quality" (like Intel with the Mhz-race for the cpu) being sure that the normal customer doenst know what quality means in typographic terms. Nowadays we can all see that is impossible to buy a normal 300x300dpi inkjet to print for example just b/w text documents at low price (like an old Deskjet 500).
Marketing Research tells that customers now want the so called "photo" quality so that we're now overcrowded by all these 2400dpi printers that have NO option to print for example in less than 600dpi.
* Read the details in the "Cost-per-page" section.

--> Avoiding the possibility of using only b/w colors.
To push the user on throwing away more money as possible on inks a good method is to forbid him to print using only the black color.
This way is well known in low-end deskjets for example.
Using this trick the printer is programmed to use a "composite" black instead of pure pigmented black, or in other cases to request the mandatory presence of a working color cartridge even if we wanna print b/w.
* Read the details in the "Inks & Cartridges Explained" section.
--> Promising amazing quality but ONLY using HP paper.
This is maybe the only thing that technically makes sense.
Every printer in the world is programmed, tested and certified to achieve a "Gamut" gamma output on specific papers only.
High-end models are very flexible about it and in many cases can be programmed by color experts to work good even on Epson paper for example.
Low-end Deskjet are UNprogrammable, not because they suck but to avoid customers on using 3rd party papers and enslave them on buying only from his local HP dealer.
(note that HP paper is the most expensive and is in part made by Xerox).
In this case using HP paper is the ONLY way to achieve decent results.
* Read the details in the "Inks & Cartridges Explained" section.
--> Forcing the printer to be INcompatible with standard inks

To avoid the customer buying refilled or 3rd party inks HP changes the size, the electronic and the ink chemical of the cartridges quite often, even in models that have similar specifications.
Doing this is quite difficult for refiller companies to stay in business, because actually they're just able to make inks for the old deskjets but not the new models.
* Read the details in the "Refilling Explained" section.
--> Forcing inks to expire after a short date

This is one of the most offending and poisonous techniques.
In many new high-end products like DesignJets apart all the tricks discussed before HP now puts a smart-chip on each cartridge, officially for a more accurate diagnostic.
--> While is it true that diagnostic is much improved and sharper, these results can be achieved even without a protected chip.
--> The cartridge will be "disabled" after a specific time date written on it , EVEN if full of ink so the user will have to buy a new one in ANY case, moreover, HP can then predict in advance how many $ can be sucked from a customer.
--> The smart-chip drives a sensor inside the cart to detect any movement in the amount of ink.
If we try to refill it for example the chip will detect that the ink amount is greatly increased and will mark the cartridge as FAIL, stop functioning, and requiring to buy a new one.
* Read the details in the "Hacking HP Printers" section.
--> Forcing the Printhead to stop functioning avoiding "force-mode" options

In high-end products a sensor will take care of numbering the dead "nozzles" in a matrix.
(nozzles are the holes from which the ink comes out).
To avoid that customers use the same expensive print-head for too much time instead of buying a new one, the machine is programmed to detect how many nozzles are functioning (in a quite arbitrary way).
When more than 30% of the nozzles are marked "dead" the machine will stop asking for a new printhead (lets say 200 euros) AVOIDING the possibility to "force" the machine to continue printing.
* Read the details in the "Inks & Cartridges Explained" section.
--> Avoiding Customization and Software Flexibility

In order to force the customer on buying the high-end versions of a product many printers come out "windoze-only" or "mac-only".
In some frequent cases they have only support for a specific OS version like W98 but not W2000 or XP trying to force the user to upgrade to a new machine.
In many other cases the bundled driver is programmed to lock some useful functions like b/w-only, use of compatible papers etc, but unlocking this functions in the higher versions (that have normally the same hw board but with a different firmware).
* Read the details in the "Hacking HP Printers" section.
--> PostScript sw RIP sold as Real PostScript

All the high-end LaserJets and DesignJets supports natively (--> built in the firmware) Adobe PostScript Level I/II/III.
To do this HP must pay Adobe a small fee for each printer sold with PS3.
In the low-end segment instead of embedding a real PS3 parser inside the printer they make the same machine with a horrible Software-PS3-Parser masqueraded as RIP, and selling the product as "PS3 Printer capable" (note the "capable" instead of "supported" or "built-in").
--> Doing this way the driver will create a huge PCL file, send the file to the PS3 RIP that for a complex A3 color page can take no less than 20-30 minutes to process on a PIII 500.
After that sends this monster file (can be even half a Gb if you use CADs etc) via LPT or USB.
(and remember that low-end printers cannot mount network card).
--> In some cases the driver has bugs converting PCL to PS3 and there's NO WAY to solve the issue except waiting for a new driver release that sometimes never comes.
(like in the evil HP ColorPro series).
--> During the PS3 render the cpu is 100% used by the RIP and you have to wait ages to finish your work, and crashes are not rare even on Mac.
--> Making crap plastic chassis to save money on manufacturing

To make a printer cheap and let it look "consumer" and trendy, the first step is make a crap plastic chassis with poor-imitated Imac colors, instead of a good "old-school" LaserJet3-like rock-solid-chassis.
* Note that is clearly written in the proof of purchase that NO parts of the chassis are to be considered part of the warranty.
* Replacing plastic part is a huge waste of money on consumer product lines.
* Note also that no one ever read the proof of purchase.

--> Feature Creep

When a new product is designed it must satisfy the customer needs, based on Marketing research normally starting defining the most lucrous versions (high-end).
Then when designing the SoHo and consumer version, based on the final budget and price the product will be mutilated of some important features..
In the majority of the cases if you open your cheap deskjet together with an high-end one and check whats inside you will see the same mainboard, similar mechanic, similar chips, memory etc.
Often the ONLY things that really change are the chassis and the FIRMWARE.
--> The Firmware is responsible for example to limit the resolution to 1200x1200dpi or avoiding using b/w-only, connecting a network card (even if you got the socket well hidden inside) etc.
--> Other cases are the ones where the firmware is "locked" to receive only one printjob at once and only from one user at time, while the "high-end" version is unlocked and cost 4-5 times more.
--> To avoid that smart users can force a firmware upgrade to the high-end version the flash-updater program is locked to avoid this and download the firmware is often forbidden to users not subscribed to the online support where is checked their s/n and model.
-->Confusing Cost-per-page DataSheets

Read well the "Cost-per-page Explained" section.

INKS AND CARTRIDGES EXPLAINED

In order to fully understand anything related to ink-jet printers we must first know the details inside the printing process.
We'll now see a brief basic description.

--> Cartridge

There are many types of HP cartridges, based on supported resolution, model, capacity, color, etc.
An HP cart is composed by the ink supply and the printhead, packed all together.
The high-end printers have separate ink-cartridge-only with a vacuum-tube-system that sends the ink to 4 or more separate printheads for an amazing quality.
This way the user can have change the colors while printing and have an ink storage of even 1 liter for color.
In the consumer printers we have only embedded ink+printhead solutions, or worse, like 1 cartridge for ALL colors.(--> "composite").
The supply is designed as a plastic box connected to a pluggable mechanic carry.
It communicates with the printer via many electric contacts on the back of itself.
This electric contacts are nothing more than a kind of "matrix" to tell the printhead which one of the nozzles must fire out an ink drop.

* PrintHead The "core" is the printhead, an electric-driven matrix of micro "holes".
Each hole is connected electronically to the matrix part in the back of the cart and is called "NOZZLE".
Each nozzle can make only one ink-drop at once but they can do it all together in various speed depending on resolution and software settings.
The size of the nozzle determines the size of the ink drop so the maximum resolution we can achieve.
* The measure unit for an ink drop is the PICOLITER.
Old carts were designed to produce an average drop-size of 20-30 picoliters, nowadays the drop-size is 3 picoliters (for a 2400x2400 dpi res).

--> Inks

You can read entire books realted to inks.
I'm not gonna write here a bible but lets see just the basic things to know.
There are mainly 4 different inks : C (Cyan), M (magenta), Y (Yellow), K (Black).
With the combination of these 4 colors the printer using the half-toning matrix is able to "fool" the human eye and create tens of thousands of shades.
Note that these are NOT real colors, just a pattern of the 4 c-m-y-k ones.
Each ink is developed and tested to react chemically with specific kind of paper and bring the user an acceptable color output ("gamut").
The paper factor is the most important.
How can an ink compound give similar colors on papers SO different ? Well, its done by the halftoning matrix that driven by the driver settings fires up less drops using for example lucid paper and the opposite using coated paper.
Without using this techniques it could be impossible to print on so many papers using the same inks, you should need more inks for each kind of media.
--> Of course HP guarantees good results ONLY using HP medias and i agree.
Why sould someone guarantee good colors using Epson/Xerox paper ? (the word "guarantee" in the hi-end printers means that the customer can SUE the company if colors are not Pantone/etc!).
HP has an entire chemical lab division for the development of inks.
The second thing an ink must do is to be able to be squizzed out in very small drops.
The actual printers can make 3 picoliters drops for example.
This is fundamental to achieve HIGH-res, old inks for example are not capable of achieve even 600x600, making drops of even 30 picoliters.
Some problems can be encountered using special medias.
While some colors react fine on normal papers, it can happen that using an expensive media one of the 4 colors doesnt work good and therefore the color output tends to be greenish or dark or too bright.
This are common issues on high-end machines and the only way to fix it is using a RIP or trick with the driver settings but in the average cases it should be considered a "product feature".
Lets stress that is almost impossible to make an ink that works fine on all the media types and in all resolutions.
Every ink has a lot of limitations as every chemical compound.
Many have also limitation regarding the dry-time or athmospherical factors like umidity, light, etc.
Its a hell for a company to guarantee results with so many factors involved.
Thats why some machines are sold with just the basic possibilities and supported medias. Last, inks must not react with adjacent drops, otherwise it will create a color-melt.
Achieving all these results is quite difficult, that explains why colors from different brands are so different in gamut, prices, and performances.

--> Half-Toning

Half-Toning is a quite old but effective technique to represent colors on paper.
Its based on the concept that the human eye cannot see all the dots in an image from a short distance.
That means that using the 4 CMYK colors we can create unlimited patterns of "colors" and the human eye will be fooled in seeing real color shades while we just used cmyk.
Technically is a color matrix where we define wich nozzle the printhead must use based on a specific color-scale embedded into the firmware.
You can NOT change easily the half-tone matrix except using specific RIPs and its only possible on high-end devices.
Even if you could i suggest you to avoid it unless you're a real color-professional.
Note that the resolution factor here is very important.
A 300x300 printout will never make acceptable colors from a short distance, but will be good to see from 1-2 meters.
Nowadays we can use 2400x2400 hires printers so this issue is no more important at least for photo applications.
Each company use its own halftoning patters and optimization alghorithms.
This way the same file can have HUGE differences regarding color outputs if printed by instance using an Epson or an HP printer.

--> Resolution

Resolution is a mix of 2 factors :
- Hardware resolution
- Ink Resolution

The measure unit is the DPI (dot-per-inch) and common res are 300x300/600x600/1200x1200/2400x2400 and some other variants.
The hardware res is the amount of dots that the printhead is able to produce in one inch.
(horizontal dots * vertical dots = resolution).
Note that in order to do that there are also many other mechanical tricks involved.
The Ink resolution is generically meant as the dot SIZE.
To achieve a REAL hires 2400x2400 the ink drop should be around 3-4 picoliters.
Some cheap and some old printers were instead sold with a hardware res of 600x600 but with inks just capable of 300x300 dots.
The results in these cases are of course not good except for a home user.
To get a REAL resolution you must have both printheads and inks capable of supporting a specific res.
Note also that there are even here many tricks to fake the human eye, and also to FOOL customers.
The most typical example is INTERPOLATION that claim to produce a double-res shifting the printhead of half a dot and printing another halftone mask.
Using interpolation is never good, expecially because apart producing faked hi-res prints the dots stay bigger that supposed and the entire process is slowed down a lot.

REFILLING EXPLAINED

There are lots of companies right now selling so called "refilled" cartridges claiming full compatibility with most common printers like hp deskjet, epson stylus color etc.
Often you can even find this no-brand supplies in your local supermarket or tobacconist.
The fact that original supplies have poisonous prices force many users sick of paying big money to print their stuff on buying "cloned" cartridges" in the hope of making a bargaign.
Lets analyze in detail whats really inside a refilled cart and why in many cases it can be a waste of money or damage our printer.
Having read the section "Inks and Cartidges Explained" we should have a clear idea of how the printing process is made.
To clone an HP cartridge a manufacturer must produce a poor copy of the plastic container, of the small electronic part (one thin flat cable) and more important --> the printhead containing the nozzles.
While the manufacturing of a printhead that produces ink drops of 14 picoliters (--> 300/600dpi) is nowadays not so diffucult, its harder and expensive to make one that does 3 picoliters like in the newest printers supporting 2400x2400 dpi.
A normal refilled cart can easily achieve resolutions of 300x300, 600x600 but hardly 1200x1200 or more.
There are some refillers that claim to achieve this high-res but you have NO WAY to be sure of that without checking with specific expensive devices or at least with good lens how much the ink drop is big.
In many expositions you'll see companies selling this kind of cloned supplies trying to fake gullible users showing them high-quality printouts specifically pre-made.
* note that is much easy to fake high-res quality printing photos than complex technical files.
They normally try to show you printouts with naked girls etc but never an electronic datasheet.
From my own personal experience in the best cases i found good 600x600 dpi cartridges but never ever real 1200x1200dpi ones.
Another point is the consistency of the nozzles and their durability.
Many refilled supplies have NOT all the nozzles with the same sharp size, that means that some of the drops will produce 13-14 picoliters, others 20, others 10 etc.
These are very hard details to see for an inexpert home user but are very clear while printing sharp cad/cam projects expecially in A3 format.
Durability also have absolutely no warranty being 99% of this cloned supplies companies nothing more than fly-by-night operations, often with even no-brand at all.
The interesting part is the real refilling, that means you already own a real empty HP cartridge with a real HP printhead that does real high-resolution.
I've seen many cases where the refillers sell used empty hp supplies with their home-made inks.
This cases are maybe the only good ones to take in consideration to save some money because at least the most delicate part is an original HP supply.
* Take care that even if the printhead is original you dont know how many nozzles are DEAD.
Theoretically can be even the 50%, causing missing lines, ink drops and other unacceptable behaviours.
Lets explain now the delicate ink chemical part.
Refilled inks are normally water-based, in rare cases they add some pigments to claim them as --> "pigmented black".
Again, you've NO proof of it unless you can try it before.
The gullible user has also no way to ensure that while a cloned ink prints good on plain paper it does that also on photo or glossy paper.
Another important point is that to refill you need in most case to put the ink in the cart from a hole, doing that you change the pressurization inside the cart so you can hardly achieve the original one.
The industrial process to manufacture original supplies is quite sharp and tested using very expensive machines assuring a perfect pressurization, ink ratio, bubble cheking etc.
Doing this at home is a matter of luck and trial&error.
This process can cause bad quality after a few dozens of good prints and in some cases missing print at all if there is too much air inside the cartridge in the form of air bubbles.
What you can easily encounter is a decent quality with rare "ink-drops" somewhere due to poor quality of the ink-mix of air bubbles, pressure and fake inks.
The most important and delicate factor is the ink/nozzle mix.
Being not sure of what kind of cloned ink are you using and not even of the real nozzle's size, having a linear good quality is far from being an easy step.
Last but not least, lets stress the fact that you have no warranty that the electronic part of a cloned supply will run flawlessy.You cannot exclude the possibility that it can short-circuit one or more signals and damage your printer's internals.
The reader can now have a wider look at the refilling market taking his own conclusions.
While for a decent and cheap econo-mode print of text documents in 300x300 or 600x600 refilled supplies can be a very good choice, for hi-res on photo paper i definetely suggest to AVOID them.

WATERMARKS EXPLAINED

There are rumors in the internet claiming that every printer embeds secret marks, logos, or hidden micro-shapes to recognize from a document which model had been used.
People claim with no technical datas at all, that this hidden, unwanted and unremovable "feature" can be even be put on special fonts, being invisible at the human eye but recognizeable with special devices used by scientific police, fbi, cia, europol etc.
As far as i know these are just URBAN LEGENDS.
There are more easy way to reverse a paper document in order to get these informations with no need of special techno-cop-devices.
Lets see in details what we can reverse from a document written for example with an HP DeskJet.
--> 1 - Fingerprint

On each paper sheet we use is quite easy to trace at least one of our fingerprint.
The police with a good fingerprint can trace back the real identity of a person, but not which printer was used.
To avoid it the only way is performing the entire printing process wearing gloves.
Buying a new set of sheets, putting it in the printer tray and printing, always using gloves.
Even using gloves and leaving no fingerprints at all the cops can trace back at least which brand of paper was used, even if it was common plain paper.
--> 2 - Colors

With good lens we can zoom and see with our eyes if the black color is pure or "composite".
(--> made with CMY colors) This way is possible to shrink the possible targets in case someone want to know just the printer's family.
(ex : low-end Deskjet or high-end OfficeJet).
--> 3 - Ink Drops & Satellites

After having checked the black factor, with some more professional devices is possible to measure the ink-drop-size in order to detect which resolution has been used , type of printhead and expecially number of "satellites" in the ink drop.
Satellites are very important : - when we draw a dot the printhead fire up one ink-drop, the drop drawn on the paper is just a small circular dot for our human eyes but if we zoom it we can easily see a range of 5-10 micro-dots around it.This micro-dots are called satellites and each kind of ink on the market has a specific range and properties regarding them.
Some special inks are "satellites free" to claim that the quality is higher.
This is true only in technical drawings, instead more satellites makes a better visual quality when printing photos due to the "smoothness" that they creates between the dots.
- Counting the number of satellites in the dot will reveal which ink has been used, and trace back the brand and family model.(ex: Deskjet instead of OfficeJet) - Techno-cops can also use a more rude approach, analyzing the ink in laboratory and ask the manufacturers the chemical compounds datasheet to reverse back the results in order to gather brand and family model and in some special cases the exact model name.
--> 4 - Country

As explained in the first chapters, regarding HP, there are NO "country-specific" printers.
In Europe for example only high-end printers are made, deskjets etc are made in Singapore or in some cases assembled in Ireland, shipped in Grenoble and bundled with local manuals but there's no way to trace back the country of a printer's user, even from the s/n.
The s/n can only be used to trace back WHERE the printer was sold but it needs the cops to ask confidential information to the sales division of HP.
(An easier way is to just call the HP tech support giving them the s/n and use some obvious social-engineering techniques).
--> 5 - Halftoning & Watermarks

There's indeed the possibility that some printers have been secretely programmed to embed in the half-toning a random watermark to identify itself, hidden in some particular fonts for example.
As written before i have no data of the real existance of these features but the possibility is real.
To ensure of the truthfullness of this theory the only way should be to disassemble the firmware and check the halftoning matrix pattern.

COST-PER-PAGE EXPLAINED

The most confusing marketing propaganda is regarding the "cost-per-page" factor.
This is a very important field because it impacts the REAL hidden costs of a printer and is always misperceived by customers, while being abused by marketers.
Lets see in detail the truth about it and why it makes NO SENSE to speak of "cost-per-page" at least regarding the average home users.
The impossibility to calculate a good, sharp cost-per-page can be explained simply because there are TOO MANY factors involved, causing even the most detailed report to become a guessing.
The factors involved are mainly :

--> Paper type

It must be clear once and for all that the printer uses different halftoning matrix for each type of paper and for each resolution.
Each paper has a huge number of chemical properties, how it reacts with inks, how much ink it absorbs, how the colors are brilliant, and so how the halftone must be programmed in the firmware to achieve decent colors on many different medias while using the same ink type.
Diffentent Halftoning matrix affects how MUCH ink goes out of the cartridge.
For example plain paper absorbs a lot, while glossy much less.
Selecting from the software driver "plain paper" and then using satinated glossy for example we will see that a lot of ink drops off the page, due to the low-absorb ratio of satinated/lucid glossy.
Thats why in the halftone matrix the glossy uses a lot less ink than plain paper while having greater colors thank to his "lucid" property.

--> Resolution

Resolution is the second most important factor.
Normal printers let the user choose between some preset factory defaults like "economode", "normal", "max quality", "b/w".
These settings tell the printer which halftoning matrix to use.
High-resolution printers eat a huge amount of ink compared to old one.
This is ONLY good for printing photos.For a normal text document 300x300 is far enough, 600x600 is necessary only for very particular and complex fonts or technical cad/cam projects.
Using 600x600 you will use 4 times the ink of a 300x300 print.
With 1200x1200 16 times and 2400x2400 64 times.
As you can easily understand using hires is a crazy WASTE OF MONEY being the average user printing in the 90% of the cases just a text doc using M$ Word.

--> Interpolation

Many printers have also extra features like "ultra high quality", "max res - high quality", and other esoteric names. What all these features do is in general a simple "interpolation" and a more slower and accurate "multi-pass" print. This kind of techniques are usually found in high- end products but also in photo-oriented Deskjets. Actually they're nothing more than tricks to get a fake higher resolution and claim it in the product propaganda. (older high-end deskjets were 600x600 but sold as 1200x1200 "capable" using interpolation). What is important to know is that using multi-pass tricks the printer will drop even the DOUBLE of ink necessary, using a special halftone mask, in some cases putting more than one color in the same dot (thats why this option slows down the process and why it can be used only on special papers). Interpolation techniques are intended to put drops between 2 or more adiacent dots but you can easily understand that is a fake "double-res" because the drop-size is still the same.It results anyway in a double amount of ink that has to be used and in any case all these techniques dont produce the same quality of a real 2400x2400 or higher.

--> Composite Black

The black color is the most important in printing, and the HP one is with no doubt the best in the market, expecially because in most of the cases is also PIGMENTED-based and not water-based as the other 3 colors (CMY).
This results in a great, lucid black, perfect for text, cad/cam and photos.
(There are many urban legends on the subject HP-black VS Epson-black).
But in higher resolutions some papers cannot react chemically in the proper way, often because the printing speed is too high or because the pigment reacts with the adiacent colors creating a melt of unwanted colors.
To avoid this problem the firmware is set up to produce the black using only CMY colors ("composite") and this means a weaker black lucidity together with a LOT of ink color wasted off by the CMY cartridges.
(note that all these details are obviously not clearly written in the software driver).

--> Printing Content

After having explained the physical details of the printing-mix (paper/res/quality), there is the most random and confusing factor : WHAT we print in a document. Some users print just text documents, web pages etc, taking care of using low-res, plain paper and economode.This is the BEST way to save money on printing.
What is cause of misperception and randomization of the statistic is what the average users print.

There are too much segment of users : end-user printing just text, end- users printing just photos, others printing just from excel/powerpoint (mixed text + photos). Moreover there are cad/cam users that print also text-only, dtp and excel, all together. Thats why declaring a cost- per-page factor is so difficult, abused, and also dangerous for the company (infact you will only see "minimal" cost-per-page in the depliants, never "average").

--> Benchmarks

People that want to benchmark cost-per-page can only make a very complex diagram with different statistics for each kind of paper and each resolution printing only text, or only vector graphic or only photos.
This way you can have an approximate idea of the real costs.

--> Conclusion

Cost-per-page datagrams are more or less faithful when we talk about b/w laserjets or high-end color-only plotters for the simple reason that those users are known to print almost always the same stuff.
What makes not much sense is talking of cost-per-page about Deskjets and other home-user printers.
I suggest the reader to have NO faith in all the esoteric datasheets related to cost-per-page that can be found in the printer's manuals or on the web.
The only rule should be to definetely realize that QUALITY COSTS A LOT.
* See also the section "Buying the right printer".

HACKING HP PRINTERS

Unfortunately despite the section-title there's honestly not much to crack in a printer, apart refilling and hacking of some internals, but there are still many malicious interesting cases to study :

- How to print in LOWER resolutions
- How to force B/W mode
- Using an UNsupported OS
- Firmware UNlocking (product "upgrade")
- Smartchip-protected Cartridges
- Firmware Debugging
- Remote Firmware Erasing
- Remote Exploits
- Driver "hacking"
- Applied Printing : FAKE Banknotes

--> How to print in LOWER resolutions

How can we save money printing in unsupported low-res like 300x300 ? Well, in newest printers officially you cant, the lowest res is normally set as 600x600.
Depending on your model, you can in most of the cases try the manual approach.
Check your printer's datasheets on hp.com and developersolutions.hp.com for additional PDFs.
There's the chance that your model can print in 300x300 or lower using this PJL opcode : @PJL SET RES=<res> (es : @PJL SET RES=300)

You must create your file, then edit the header and change/add this string before the @PJL SET LANG=xxxx one.
Skilled crackers can of course hack the driver itself to avoid using the manual approach every time.
Note that some printers does NOT react to value minor of 600, or they dont use PJL at all.
When this happens is because the firmware is coded to dont care on lower values.
In these cases there's not much else to do, i'm sorry.

--> How to force B/W mode

Same as above but the PJL string is : @PJL SET MODE=MONO or @PJL SET COLOR=MONO

--> Using an UNsupported OS

How to print under UNIX with a Windoze-only printer ? There are just 2 ways : Using Ghostscript, CUPS, or a print-server under NT/2K.
Just remember that almost all HP printers support PCLxxx and many also PS3, HPGL3, RTL and CALS.
The issue is that there are many different versions and implementations of PCL.
Read carefully the PDFs on developersolutions.hp.com then check if your version of ghostscript or CUPS supports at least your printer's family (es : Deskjet 5xx/6xx/9xx) and create your own "FILTER" (not much difficult).
Note that you can also just use a generic filter, but this means you will not be able to use the advanced features of the printer.(es: hi-res, color-management, ICC profiles,etc).
This is good only for print b/w docs but i suggest to use a print-server for photo applications or serious color hackings.
Issue : you're using a Windoze-only printer like the Deskjet 720.
Well, there is an HPPA parser for ghostscript but it sucks in my opinion.
In these cases is better to use a remote print-server under Windoze that is controlled by UNIX using LPD/IPP or whatever protocol you like.
From my personal experiments is much simpler and better to always use a print-server unless you just want to print text docs.
(you need NT4 server/2K Server, just install the "Printing Services" and "UNIX Printing Services" or for Mac the 3rd party "PC Mac Lan 8.xx").
Using a print-server you'll also be able to print from Macinto$h using the simple HP-laserjet utility for Mac (tcp/ip only).

--> Firmware UNlocking (product "upgrade")

BRUTE FORCE APPROACH :

Issue : your model doesnt support all the features of the higher one but you know that is based on the same identical board/cpu/etc.
For reason of space i cannot write a list of the hundreds of HP printers capable or not of flash-bios, PS3, simm-rom, locked eeprom etc.
As a reverser you should know where to find these details in the vast hp.com web site and the multitude of subdomains (in primis developersolutions.hp.com), if in doubt contact the author.
Many low-end printers are nothing more than the hi-end version but with "locked" features.
Unfortunately only mid and hi-end printers support flash-bios upgrade. In these cases just grab the hi-end's firmware file from hp.com and send it directly using an LPT cable (using DOS or unix, *NOT* the stinking HP Flash Updater because is "locked" and does not let you force the upgrade).
If the printer has a Jetdirect Card, you can also send the fw via IP using for example NETCAT by Hobbit.
--> netcat <firmware.bin> <IP> <port> --> ex: netcat firmware.bin 192.168.0.1 9100 <-- port is always 9100.
** be very careful, if the flash fails your printer will be fucked up.
*** dont try to flash a PS3 firmware on a low-end, postscript is always inside a separate "simm-rom" module and cannot be flashed/upgraded except on special high-end models (where the ps3-bios is stored on hdd and can be even 130Mb).
Unfortunately it seems that no-one of the cheap deskjets are flashable unless you use take off the chip and use an eprom/eeprom programmer.

--> Smartchip-protected Cartridges

Some high-end inkjets are bundled with huge ink-only cartridges, connected with a vacuum tube system to the printhead.
These carts are very expensive (lets say 200 euros) and contain even 1 liter of ink.
Due to the HP's evil politic against refillers, there is now a smartchip on each cartridge designed to detect sabotages, refilling, and tweaking.
Inside the cart there is a sensor to detect sharply the amount of ink.
The value is written inside the smartchip itself, NOT in the mainboard's flash-rom.
The smartchip contains also other datas like umidity factor, s/n, system date and the infamous EXPIRE DATE.
Its "officially" impossible to modify any of these locked values, nor you will find any useful information on the web.
However, as for any smartcard/smartchip/sim/etc there is a very easy way to reset and change ALL these parameters, knowing in advance the smartchip memory mapping and how to have to access to it.
To access the data you need to write a PJL file embedding the "secret" TCL opcode for address-cell datawriting (which i'm not gonna tell you here).
Sending the file via raw LPT or IP will "execute" the micro-script on-the-fly.
In this way is possible to reset the expiration date and the damn anti-refill-sensor.
As far as i know is also possible to clone the entire smartchip from a brand new cartridge in order to refill an empty one.

--> Firmware Debugging

The only way to even think about starting firmware debugging is to have a fresh copy of VxWorks,( find the details on their web site www.windriver.com).
There's a free evaluation package with tons of .pdf files but not much advanced support for many cpus, just the basic ones.
In order to debug your printer you should unmount it and see whats the cpu model.
If its not supported by your VxWorks' eval-copy than you need the full version with ALL the cpu files, search the web and grab it down.
(--> very very difficult to find).
You need also your printer's fw file otherwise you should try to rip it off by yourself using special hardware readers.
Keep in mind that using VxWorks at home makes only sense for testing purpose or to debug flash-bios-enabled products.
Note also that fw are often crypted.
Once you have selected your target you can start learning the printer's cpu assembly and play with it.
Lets stress that some firmwares are quite small (100kb) but others are monsters of 120Mb if embedding PS3, PS Fonts etc.
If you are REALLY but really fed up with your printer you can try to debug and patch the firmware but actually i suggest you to asolutely AVOID it unless you're already familiar with embedded devices and VxWorks.
Apart my suggestions, learning VxWorks is a highly considered skill nowadays in the embedded-devices' industry and every good reverser should at least try a "test-drive" with it.

--> Remote Firmware Erasing
I explained before how to brute-force a flash-bios upgrade.
It seems strange but HP printers have NO protection at all for these things.(of course only the ones supporting flash-bios).
Being malicious guys we can fill the fw file with zeros (except the header) using Ultraedit or any hex-editor and send it to the enemy's printer to completely fuck it up.
What is amazing is that there are almost NO checks whatsoever, even in printers costing 40.000 euros.
After this operation the printer has NO way to come back to life and the victim will have to change the entire mainboard.
(as far as i know the firmware has NO "boot block" sections).
If not enough, is possible to send via IP also a "zeroed" firmware for his JetDirect Card to complete the attack.
Similar process in case the enemy has a rack-mounted HP spooler "print-server", HP ProCurve stacks, and other HP network switches.
* note : Some of these models could give you a "checksum" error, then just create a file full of garbage but with correct cheksum.
* note : this kind of funny tricks are conceivable on a big LAN/WAN, i discourage doing it on internet or via email, batch files, vb scripts etc due the huge size of the fw files.
* As far as i know HP tech support can only diagnose these cases as a kind of "no post, no leds, no power on" symptoms, and replace the mainboard in warranty or bill the owner if warranty is expired.
Its almost impossible to trace you back, or the IP used to send the fake fw because JetDirect Cards always reset their poor logs after a "successfull" fw upgrade.
Moreover, after having "zeroed" a firmware nobody will be able to read logs (in the few models that support IP logging) or do anything else.

--> Remote Exploits

Remote Exploits are only regarding HP JetDirect Cards (the only network card used in HP printers).
On the web you can find some old exploits for early jetdirects or in conjunction with HP JetAdmin software.
(JetAdmin had a root exploit in older versions like the 6.xx).
Early versions of jetdirect had the option to be used as PROXY and with NO LOGS.
Of course this nice feature has not been implemented in newer versions.If your LAN has still these prehistoric jetdirects you can try to downgrade their fw and use them as full anonymous proxy.
Some high-end printers (es: Designjets) have a 20Gb hdd as storage and PS3-scratch-disk.
Connecting via IP or even HTTP (embeddd web server in newer jetdirects) just activate the FTP, and you can use it as remote storage for your own files (a private LAN ftp).
(the printer just process the ps3/hpgl2/rtl files but holds in hdd every other format).
Newer jetdirects support also SNMP and IPP protocol offering a full remote IP management, even over the internet but i'm not aware of any remote exploits with these cards at the moment.

--> Driver Hacking

Before talking of driver hacking keep in mind that ALL the documentation regarding printer's languages like PCLxx, PS3, EML, HPGL1/2/RTL etc and also some dev-kits with source code and .pdf files can be freely downloaded from http://developersolutions.hp.com Most HP drivers have some small "easter eggs", often by pressing F8 or other function keys in the "about" field inside the driver's property panel.
Using any resource-hacking tool like BRW/Symantec Resource Studio you can see not only "hidden" settings panels to tweak the printer but in some cases also the UGLY *photos* of the low-paid enslaved developers.
There's not a common rule to access the "hidden tweak panel" and not all models have it.(high-end models all have it) First of all the driver must be HP and not the one bundled with Windoze.
Many uses the F8 key but others dont, or require the combination of mouse and keyb together.
(and I'm not gonna write here all the hundreds of shortcuts for each driver, as a reverser you should find them by yourself).
If you're unsatisfied of your driver's customizability or performance you can have a good time writing your own.
All you need is M$ VC++, the M$ NT/9x/2K DDK (freely downloadable) and the HP's DDK for your printer family (this too is free).
Keep in mind that HP drivers are already quite good (compared to Epson and Canon) and the few bugs you can have encountered are on 99% due to dinosaur DTP programs made by low-paid slave-engineers (--> read *Corel Draw*).
A good thing to play with can be the porting of a printer driver to UNIX, quite fast expecially using GhostScript or CUPS.
(you've just to write a "filter" file defining all the printer's characteristics).
Note that what you can do is just write a "generic" filter because MOST of the product-specific opdodes and specifications are NOT public except if you're a 3rd party that paid a hugh fee to have the full dev-kit.
(so they can even track you down if you unleash these details in public).
The main limitation writing your own driver is that you can NOT drive the mechanic or write down from scratch your own half-toning matrix.
To do this you gotta use a printer internal language such as EML/Varware/etc that is absolutely not much standard and has custom opcodes for each models.
A much more funny approch is creating real-time scriptings with TCL (that again, i'm not gonna explain here) to drive the printer's internals.(--> absolutely useless if not for fun or hacking).
* note also that creating your own halftoning matrix is in the best case a total waste of time, unless you're working for a company developing a RIP (raster image processor) or you really know what you're doing.

--> Applied Printing : Fake Banknotes

There are many urban legends telling about youngsters faking banknotes using high-res inkjets..
Lets clarify once and for all that is NOT possible, even with special inks (you have not the right paper, and you can NOT find it), or special hologram-devices (forget it).
First of all, even scanning a banknote at amazing quality, your hires printer will never be able to produce the wide gamma of *colors* of a real euro and you cant print the hologram, timbres, trasnparency details and silver lines.
Moreover, even if i could ever know the manufacturing process be sure i'll never write it here.
What can be funny is instead the cracking of electronic devices accepting banknotes of 5/10 euros (like the evil slot/poker-machines, coin-changer, Sigarettes-machines and other small "cheap" devices).
** Do NOT even think about trying with gas-stations, ATM, banks etc.
Common cheap banknotes-loaders follow normally the same basic process.
When you insert the (fake) banknote 3 "scanner-leds" (note : 3 because they're RGB, but your printer use *CMYK*) scan the beginning and compare the scanned image (as far as i know NOT more than 150 or 300dpi), with the one resident in their flash-rom (re-programmable using dip-switches).
There is of course a great "tolerance" factor to avoid refusing all semi-used, old, or dirty banknotes.
If the first test is successfull the mechanic loads the rest of the banknote and then check all the other important parameters (and here there's NO tolerance factor) like exact lenght, width, shape, size.
Some more complex ones also perform a simple check to detect the paper type.
This is done calculating how much time it takes to load the paper based on a comparison matrix inside the firmware.
(so in this case a good choice is to avoid lucid, glossy, photo and plain paper and prefere low-weight opac-high-glossy, the only one similar to banknotes).
If step 1 and 2 are passed successfully the machine then perform a scan of the entire banknote (in cheaper models only SINGLE SIDE).
Now the damn machine compares a low-grade 150 or 300 dpi *RGB* image with our hires 2400x2400 *CMYK* one.
There is a tolerance factor, depending on the model, in cheaper ones is quite high (5-10%), in good ones is minimal.
How much then is important the RGB vs CMYK factor ? I think i've written enough on this subject and gave you enough details.
Using the good paper, scanning at best quality, and printing in max resolution and details you *should* be able to fool at least older sigarettes-machines..
Unfortunately after the advent of the euro most of these machines could have been "upgraded" to newer and complex banknote-readers.
For any doubts read from scratch this essay.
** i'm of course NOT legally responsible for any damage you could do.
this section had been written for *didactic* purposes only.

BUYING THE RIGHT PRINTER

Having read all the contents of this brief essay the reader could ask himself what is then the right printer to buy.
First of all i suggest to keep in mind all the sections discussed before and then clarify whats the main thing he needs from a printing-experience.
Knowing exactly the need will close the possibile candidates to few ones so the choice will be quite easy.
By opposite, having no idea of the real needs will just produce a waste of time and money.
As last section in this essay i'll briefly explain the important differences between the key players in the printing-arena so that the reader can have an idea of what fits best for him.
--> Hewlett Packard

HP use "classic" ink-jet technology.
(This way the dot-size cannot be changed.) HP pigmented black is absolutely the best in the market.
(very important for text-only documents).
HP cartridges embed the PRINTHEAD, so when you buy a new one all the nozzles are brand new.
HP has the wider driver support for any OS and is the company that sets the "standards".
HP has a 24h ONSITE warranty bundled with the product by default.
HP Toners, parts, and consumables can be found everywhere in the world at fair price.
--> Epson

Epson use "micro-piezo" technology, an "improved" classic ink-jet.
--> the key difference is that micro-piezo can CHANGE the dot-size, very important in hires photos, not much for the rest.
Epson has inferior color-gamut compared to HP.
Epson has NO onsite warranty bundled with the product, and spare parts are very expensive.
Epson has NO printhead embedded in the cartridge.
Epson drivers have inferior quality and support by major graphic companies and OS.
Epson cartridges are much SMALLER than HP while costing only few euros less.
Epson is with no doubt the best choice for photographers and photo-only applications.
--> Canon

Canon claims to use "bubble-jet" technology, that technically is a clone of classic HP's inkjet.
Canon printers never had good reputation, expecially because they tend to focus in the low-end market segment only.
Canon's chassis are 100% cheap plastic, the worst i ever seen.
Canon's drivers are not well supported by all the OS.
Canon too has NOT onsite warranty bundled with the product.
Canon colors are fairly "unusual" and aimed for low-end applications.
I would never suggest to buy a Canon inkjet personally, by opposite high-end laser printers, copiers, fax, scanners and cameras are fantastic.
--> Lexmark

I would not even take in consideration Lexmark, that used to produce cheap "re-branded" products for Compaq, IBM, Olivetti, and other OEMs.
While it can be a decent choice in some segments of color-laser and high-end lasers, the inkjets are awful, cheap, poor in design, performance, driver support and global quality.All this for just few euros less than a good HP or Epson.
--> Others

Other brands are to be considered "toys" and to be carefully avoided.
I've seen and used many no-brand printers sold for 50 euros or less, often bundled with special offers in supermarkets during Easter or Christmas.
In the best scenario they're just a waste of money.Forget it.
--> "Old-School" Pin-Printers

There is the possibility that the reader disgusted by the contents of this essay decides to go back to "old-school" pin-printers.
This is absolutely the most cheapest solution for text-only documents.
There are not much printers left in this segment, but by far the best choice is the rock-solid Epson LQ series.
Fast, ultra-reliable, cheap, and very very noisy as all the pin printers.
Its a quite "romantic" choice and the tapes cost just 5-10 euros.
No more cartridges nor colors nor frills .. back to the roots.

(C) Feb 2002 SLOBOTRON (slobotron@yahoo.com) For any feedback or questions feel free to contact the author.

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