Printing Pure Cyan on Epson Printer

[gman_01]

I am trying to print out a design with elements that requires pure Cyan lines/elements from my Epson WF-7520 printer. However, even though the image element colors are set to 100% Cyan only (and the file is already in CMYK) the lines are printing as a mixture of Cyan, Magenta, and Black inks. This is frustrating because the printer has a separate Cyan cartridge. Though I presume this model printer is more "business" class and probably considered an RGB printer, it is using separate CMYK inks in the hardware to approximate this RGB color model. So the hardware doesn't seem to be the problem. It seems like the problem is in the software.

All I want is for the print-out to be pure ink from the Cyan cartridge. Theoretically, this seems attainable, yet I have had a very difficult time finding a way to accomplish this.

I am aware that using a different printer might remove this difficulty entirely, but unfortunately I need a solution that will work on this printer. 

I saw an online suggestion to save the PSD as a PDF and print through Acrobat Pro in order to use it's native proofing and color separation features. I am not an Acrobat expert however, so after saving as a PDF and opening it in Acrobat I haven't found a way to accomplish this goal with the settings available.

P.S. It might even work if I could get the whole image to print in only one ink color; even another color. For instance it might even work if I could get pure Magenta.

[Per Berntsen · Accepted solution]

Inkjet printers use CMYK inks, but expect to fed RGB files. So it's possible that the printer does a double conversion (CMYK to RGB to CMYK), which may be part of the problem.

Besides, CMYK profiles are generally for offset printing, and the profile you're using will not be able to produce a saturated cyan. CMYK has a much smaller color gamut than RGB, and most inkjet printers have a much larger color gamut than printing presses.

So you should prepare the file in RGB, where 100% cyan is equal to R=0 G=255 B=255.

Then use the proper paper profile for your printer/paper combination. Printing profiles should come with the printer, or can be downloaded from the Epson website.

In the Photoshop print dialog, set Color handling to Photoshop manages colors, and choose the correct Print profile.

Also disable printer color management in the printer driver.

[gman_01]

Thanks! The RGB values work much better than the CMYK versions.

[SasquatchPatch]

If you're using the standard Epson driver, then the printer expects RGB values coming from Photoshop. The printer driver converts to CcMmYKkk on the fly which is what's sent to the printer. The only real way to print pure cyan out of an Epson is to use a true CMYK RIP that is capable of controlling the individual ink channels, but those are rather expensive and not necessary for most of us. If you have a final CMYK file to proof on your Epson it is perfectly fine to send that CMYK file the same way you send an RGB file and choose the printer profile for that printer. If your Epson paper is close in whiteness to the press paper you're using, then you can send the CMYK file using Relative Colorimetric rendering intent. If the paper whites don't match closely, and the Epson paper is brighter (more common) then you can send the file using Absolute Colorimetric and that rendering will attempt to put the color of the press paper into the white of the Epson paper. And, in fact, if you're designing in InDesign, this is a far better way to print - RIP a PDF out of your Id file, RIP that into Ps as a CMYK file and then print it from Ps. It is virtually impossible to print consistent prints from Id to an RGB Epson. Not impossible but so convoluted that it's basically impossible for mere mortals.