My workflow consists of importing photos into Apple Aperture, where I do most of my editing. Sometimes, I edit the photo in Photoshop. Aperture can automatically create a .psd file based on my edited image, and include that in its own library. The final results gets printed on an Epson Stylus Photo R2880 printer.
In the Aperture settings, I can select which color space to use when generating the .psd file. As I have set it up right now I use 16bit and ProPhoto RGB color space.
However, when opening up the color utility, I can see that some of the glossy paper color profiles for the printer contains colors that are not inside the ProPhoto RGB color space. This is mainly blue and purple nuances in the black area that are outside the scope of the ProPhoto RGB color space.
What puzzles me is that the icc profiles for my printer, an Epson Stylus Photo R2880 are not CMYK, but RGB profiles, I am wondering if I should choose one of the color profiles for that printer when exporting to PhotoShop. The annoying part about that setup is that I would have to go into Aperture preferences and select the export color space based on the papertype I wish to print on before opening an image in Photoshop.
What also puzzles me is the fact that the icc profiles for the printer use the RGB, not the CMYK, color space. Although the printer does have 8 instead of 4 types of ink instead of 4, it is still based on subtractive color, as opposed to additive color that the RGB space is.
I'm quite new to the entire color management thing, and I want to set up my system to be able to generate predictable prints, and also fully utilizing the capabilities of my printer, e.g. I can see by comparing the color profile of my monitor with the color profile of the printer that the printer by far exceeds the monitors capabilities in producing very saturated green and blue colors.
My primary workstation is an iMac, on which I have calibrated the display using a x-rite Colormunki.
Answer
Working color spaces and print color spaces are distinct, separate things. Generally speaking, you never want to directly apply a print profile to an image. The purpose of ICM is to utilize ICC profiles to describe what needs to be done when moving content from one device to another. You NEED to keep your photos tagged with an RGB ICC profile that properly describes the image in the RGB space, and you NEED to select an additional ICC profile that properly describes the capabilities of the printer. The ICM engine will then (normally) figure out how to adjust colors...according to your selected rendering intent...from the RGB space to the printer space.
To demonstrate my workflow, I generally do the following:
- Do primary processing in the largest RGB color space I can (normally ProPhotoRGB).
- Create a copy of my primary working image, and convert to an RGB color space that as closely matches the gamut of the print as possible.
- This may be sRGB if the paper is a limiting factor.
- This is often AdobeRGB, as my Canon PIXMA Pro9500 II supports a gamut that largely covers the AdobeRGB gamut
- Manually scale the print copy to the exact dimensions necessary to accommodate my print.
- If printing at 300ppi @ 19x13", I would scale and crop the image to 5700x3900 pixels.
- Perform any print sharpening necessary to bring out desired detail
- Preview at "print size" using the zoom tool (make sure you configure Photoshop with an accurate screen PPI...the Apple CinemaDisplay 30" has a 103ppi resolution)
- Soft-proof the print in Photoshop, by selecting the appropriate printer ICC profile that matches the printer AND paper I intend to use
- First and most importantly, I try to adjust black and white point to lie within the limits of the print gamut
- If necessary, more so when using Relative Colorimetric rendering intent than Perceptual rendering intent, fix out-of-gamut color (search the web for a variety of techniques for this)
- Print, leaving the image profile what I selected in step 2, and selecting the same ICC print profile as in step 4
I want to stress at least checking the white and black points when in soft-proofing mode. Using a Perceptual rendering intent when printing will usually do a pretty good job, but its easy to lose a lot of tonality in the shades and sometimes in the highlights if you don't adjust them for the specific printer and paper you intend to print on. Adjusting them in soft-proofing mode ahead of time helps maximize tonality for print. Generally speaking, you don't need to worry about out of gamut colors if you convert to an RGB space that closely matches the printer space. With modern Epson printers, that is probably closer to AdobeRGB than sRGB. If you prefer to use Colorimetric Rendering intent, then you might want to learn some techniques to fix out of gamut colors before printing, to maximize your control over color quality and minimize posterization.
Finally, once you have tuned the print copy for the specific paper and printer, save it with all your adjustments. You should be able to print from it as many times as you need with predictable results. If you ever need to print on a different printer, paper, and paper size, you should redo steps 1-4 above for each one, and save a separate copy off for each.
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