Tuesday, January 4, 2011
Color Printing Technique
The leap from computer monitor to printed output is where most professionals experience issues of color shift and a loss of punch in a photograph. Los Angeles-based pro Lee Varis takes us through the steps to get perfect prints.
Separations. Separations will be available only if you’re printing from a CMYK document; otherwise, it will be grayed out. This is used only when printing separate cyan, magenta, yellow and black “plates” or simulations, and for the most part, you can ignore it.
The last choice is Rendering Intent. Here you can choose: Perceptual, Saturation, Relative Colorimetric or Absolute Colorimetric. Ninety percent of the time, Relative Colorimetric will give you the best result. Occasionally, certain very saturated colors will tend to posterize and lose detail in the print. If this is the case, you can try to solve the problem with Perceptual rendering. Generally though, Perceptual rendering will give a less saturated color in the print, and your skin tones could become dull. The other renderings are applicable for custom profiles and unusual circumstances; however, for the most part, you can ignore them with people images.
Beginning with Photoshop CS5, the large preview in the dialog is color managed and has some check-box controls underneath the preview. Checking Match Print Colors, by default, checks the other two boxes—you can uncheck them if you desire. Gamut Warning renders flat areas of gray over any color that’s out of gamut for the selected printer profile. Show Paper White puts a tone into the white areas of the preview in an attempt to simulate the effect of the paper color on the image (much as you can with the Custom Proof Setup under the View Menu). The preview also can be used to reposition the image directly. If you uncheck the Center Image check box in the Position area, you can click the image preview and move it around on the page and/or rescale it by dragging on the corner handles in the bounding box (if you uncheck the Bounding Box, you won’t be able to do this).
Once all your options are set, you’re free to click Print. The only additional thing you need to remember is that if your color-management options are being set in Photoshop, you have to turn off any such options in the Printer Driver dialog. All of the color transformations will have taken place already in Photoshop before the data hits the printer driver, so make sure you don’t “double color manage” and introduce an additional transformation. Every printer driver is a little different, but yours will have some option to select no color management in the printer driver.
Moving directly from the document color space to the printer will give you the most faithful rendering of your image file. Sometimes you might want to simulate another kind of output with your desktop printer. The final use for the image may be in offset lithography or some other type of commercial output, but you’ll be delivering an RGB file and you may need to know how it will look in the final output. By selecting the Proof radio button in the Color Management section of the dialog, you’ll generate this kind of output simulation for your desktop printer (also Figure 4). Use the Proof option to simulate another type of output on your desktop printer.
The Proof profile is determined by your Proof Setup under the View menu in Photoshop. If you use a custom proof setup that includes a paper white simulation, you can check Simulate Paper Color and this will print a tone into the white paper of your print. The tone may look off if you see it against the normal white of the paper, so be sure to trim off all the plain paper before showing it to a client. Whether you use the paper simulation feature or not, you should leave Simulate Black Ink checked to get a better idea of the contrast of your final output in your proof print.
This article is excerpted from Lee Varis’ new book, Skin, 2nd edition. You can see more of his work at www.varis.com.
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