Chemical printing using Epson Artisan 50

[alchemy]

Im hoping that someone can answer this question. I need to know the specific colors which are assigned to each ink tank in an Epson Artisan 50. I am a scientist and plan to use this printer to print six different solutions of chemicals onto a surface. I want to print small details using solutions from individual tanks and I dont want solution A (spot A) to mix with solution B, etc. Can anyone give me some advice on where to begin?

 

[nickart]

Put some primers in e.g the A tank and print a gradient of all the colors (from each tank). Then test (e.g. Southern) to see if it is attached to the paper and where it is located. Then you know something about the cross contamination.

Have fun and let us know how it is going.

Nick

 

[Grandad35]

Im hoping that someone can answer this question. I need to know the specific colors which are assigned to each ink tank in an Epson Artisan 50. I am a scientist and plan to use this printer to print six different solutions of chemicals onto a surface. I want to print small details using solutions from individual tanks and I dont want solution A (spot A) to mix with solution B, etc. Can anyone give me some advice on where to begin?

That printer uses C/PC/M/PM/Y/K inks and has R/G/B inputs. There is no way to trigger a single, specific ink from the R/G/B inputs, as the RIP that controls the individual inks is internal to the printer. I have no experience with this, but you might want to look at devices like this - give them a call to see if it will do what you want.

 

[dparadowski]

Just stumbled upon this link the other day. Gives you the actual RGB color number need to fire each nozzle.

Nozzle Colors

 

[Grandad35]

Just stumbled upon this link the other day. Gives you the actual RGB color number need to fire each nozzle.

Nozzle Colors

These colors may or may not match the exact ink colors in the cartridge, the important thing is that the printer is drawing ink from only one chamber at a time with out mixing inks from two or more chambers.

How can the colors not match the ink in the cartridge if ink is drawn from only one cartridge? The answer is that more than one ink is used when each of these colors is specified.

I don't remember who did the test, but someone on the forum posted some impressive work where they printed various color gradients and patterns using only a single ink (a clear liquid was loaded in the other carts). These tests showed that more than one ink is used even when it might be expected that a single ink would suffice. Hopefully someone else will chime in with the link.

Note that when you specify different paper types, the printer driver uses different "icc profiles" that alter the RGB values sent to the printer in order to get the correct final color - any colors that you specify will be changed by the driver unless you know how to disable color management in the driver. There are numerous other problems with just using the color values in the link, but it would take a book to get into it.

Even if the given color values did work as described, how would the OP get less than a 100% laydown of an individual chemical? Ask yourself how can you have full control over 6 individual inks (C/PC/M/PM/Y/K) with only 3 inputs (R/G/B)?

Not everything posted on the internet is correct.

 

[dparadowski]

granddad, without starting a war. I saw this post and remember the link I posted, reread the link and thought it would be useful. If the person is smart enough to load different chemical into the cartridges, I'm sure he can click the turn color management off. I don't know if the different paper types would change the color used if the CM is turned off. I respect your input as I am by no means an expert on this, but your post gave me the impression that you think I am a moron for believing anything I see on the internet. Ink supply is a reputable distributor of Ink and CISS units and supplies, so it is not just some random posting on the internet. I believe what they meant by colors may not match exactly the ink colors in that cartridge is that the RGB values they show may not look like they do on the screen, ink cyan looks very different than on the screen. Epson can fire just those colors during a nozzle check, so I assume you can get it to do it as well if you know the correct color to send. I was just passing along something that as it was laid out was a possible answer to his question. Sorry if I am taking it the wrong way, but that's how I took it to mean.

 

[ghwellsjr]

I don't remember who did the test, but someone on the forum posted some impressive work where they printed various color gradients and patterns using only a single ink (a clear liquid was loaded in the other carts). These tests showed that more than one ink is used even when it might be expected that a single ink would suffice. Hopefully someone else will chime in with the link.

Maybe you were remembering some tests that I did, first for greyscale printing and then for color printing on an eight color printer. These tests apply to Canon printers and so may not be applicable to the Epson printer.

The way to find out is to make a set of "cleaning" cartridges that have cleaning solution in them that will leave no visible printout. Then put them in your printer except for one normal cartridge. Try printing various colors on various paper types and see if you can find a color that will cause only one cartridge to print. This is going to be a vary arduous test because you have to try all the cartridges one at a time, making sure you do cleaning cycles to get rid of residual ink.

If you had assumed that a Canon printer would only use the dye black ink when printing 100% black on photo paper, you would be wrong. That is what the website claims the Epson printer does but until you actually test it, I wouldn't rely on it to be true. It appears to me that they are jumping to a conclusion that when you specify 100% of any color, that only that color ink is used. And with Canon printers, different paper types combine the different inks in different ways to produce the same color. What else could specifying paper types do? Does the Epson printer only allow one type of paper? I doubt it. Since the website does not specify which photo paper is used, are we to assume the same result will be obtained with all paper types? This cannot be the case, otherwise there would be no point in specifying a paper type.

 

[Grandad35]

granddad, without starting a war. ....... I was just passing along something that as it was laid out was a possible answer to his question. Sorry if I am taking it the wrong way, but that's how I took it to mean.

I certainly don't mean to start a war either, and I hesitated before replying for that very reason. In no way did I mean to imply anything about you - only that inksupply posted incorrect information that would lead the OP down the wrong path.

I'm not a genius - I used to think the same thing that inksupply posted. I went into Photoshop, created a color in the CMYK color space, converted it to RGB and was "good to go". Boy, was I ever wrong!! RGB color values are relative and have meaning only within their color space. They do not specify an absolute color. Go into Photoshop and use the CMYK values in the color picker to specify pure C (100/0/0/0), then pure M, then pure Y, noting the RGB values for each ink color. Then use "Convert to Profile" to convert to the aAGB color space (assuming that you were in the sRGB color space when you started). Repeat the test and note the values.
In the sRGB color space, I got:
R G B
0 174 239 Cyan
236 0 140 Magenta
255 242 0 Yellow
25 31 32 Black
In the aRGB color space, I got:
0 172 236 Cyan
202 0 136 Magenta
255 242 45 Yellow
39 36 37 Black
BTW - these values all depend on your default CMYK color space (specified under "Color Settings"), U.S. Web Coated (SWOP) v2 in my case. A different CMYK color space would change the RGB values created in this test.

How can the same color have different RGB values? To understand this, you have to do a lot of reading about color management and spend a lot of time thinking about it before it begins to make sense.

I apologize if I offended you, but I couldn't come up with a way to tell the OP to ignore the Inksupply information without sounding a little harsh. Inksupply is in the business and they should know better.

ghwellsjr,

Yes, that was the post that I remembered. I obviously remembered incorrectly about what you posted on color gradients and got it confused with tests that I had run on my own that showed that even when you print pure "cyan", the printer mixes in some Magenta and Yellow. When you print a Cyan gradient, full strength cyan starts to be mixed in even on lighter colors as the Photo Cyan first increases, then decreases again at the darker colors in a smooth transition. Otherwise, you would see a step in the color when the two inks switched. At 50% Cyan, you get a mixture of the two, not pure PC.

When Canonfodder and I did the tests on the color of various inks and suppliers, we could have saved a LOT of time if there was a way to print with a single ink. Unfortunately, we couldn't find a way to do this and Canonfodder had to resort to a very labor intensive manual method to generate our samples.

 

[nickart]

Granddad,

So in other words, its impossible to print only from one tank? If so, can Alchemy then spot only one chemical?
Are there colors that never printed simultaneously? I was thinking along just black and another color.
What about making an artificial icc profile. Would that be an option?

Just a bunch of questions to trigger idea's.

 

[Grandad35]

Granddad,

So in other words, its impossible to print only from one tank? If so, can Alchemy then spot only one chemical?
Are there colors that never printed simultaneously? I was thinking along just black and another color.
What about making an artificial icc profile. Would that be an option?

Just a bunch of questions to trigger idea's.

Before answering your question, two additional points.
1. Have you ever considered the question: What color is red? This chart lists 25 different colors that have red in their names. The color that you see on your monitor when you specify 255/0/0 for the RGB values depends on the technology used to manufacture the monitor, the white point for the monitor, whether the monitor has been calibrated and (believe it or not) the color of the background that you see behind the monitor.
2. Here are two links that discuss different colors that are called cyan. Specifically note the statement Process cyan is not an RGB color, and there is no fixed conversion from CMYK primaries to RGB. The ink in a printer is process cyan, so ..

The printer obviously has the internal ability to print from a single ink tank, as it does for nozzle checks. However, the input to the printer is a set of RGB values that our computers are so fond of. These values have to be converted from monitor colors to process colors. For our inkjets, this is done by processing the color values through the proper icc profile and then through the printers internal RIP (previously referenced). The RIP for a printer with only C/M/Y inks is obviously different from a printer with C/M/Y/K inks and different still from a printer with C/PC/M/PM/Y/K inks. Suppose that you want to print 10%C, 20%PC, 30%M, 40%PM, 50%Y and 60%K. How can this be specified with only the three R/G/B values? Obviously, it cant. This is where an external RIP comes in it allows you to control each ink independently.

In its simplest terms, an icc profile is generated by printing a series of known RGB values with color management turned off, then scanning the print to measure what colors were actually printed. This information is then used to create a table of When I specified THIS color, I actually got THAT color. This information is then inverted to create a look-up-table of If you want THAT color, print THIS color. It allows you to get the correct color from a printer, but wont help in printing with an individual ink.

A project like this isnt for the novice. If it is work related, it will be less expensive in the long run to find someone who has the equipment and experience and contract the work to them.