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Better Color from Print on Demand
How to Improve Color Accuracy, Contrast, and Vibrancy in POD Book Covers and Color Books

By Aaron Shepard


For more resources, visit Aaron Shepard’s Publishing Page at
www.newselfpublishing.com

Copyright © 2010, 2011 by Aaron Shepard. May be freely copied and shared for any noncommercial purpose as long as no text is altered or omitted, but it may not be posted online without permission.



Book cover: POD for ProfitWith print on demand, it can be a challenge to get graphics with the contrast and vibrancy you expect from book printing—but that’s not because of POD technology. The main problem is the approach of the big POD services to color management. Lightning Source actively discourages it, asking you to remove all color profiles and prescribing an inappropriate color space. CreateSpace generously allows you to embed any color profile you want—and then completely ignores most of them. Still, you can get great color from print on demand, if you’re familiar with color management and ready to go beyond official documentation.

Let’s start with Lightning. I’m not going to give detailed instructions here, because those would depend on your software, your workflow, the needs of your book, and more. But if you’re using Adobe professional software—sorry, not Photoshop Elements—here are some basic steps you can follow.

1. Locate and install a color profile for an HP Indigo press, the liquid-ink press used by Lightning, CreateSpace, and most other POD outfits for color printing. (This profile can be found online.) This may not be the exact profile for the press model and paper being used, but it will be much closer than Lightning’s prescribed “U.S. Web Coated (SWOP) v.2,” which is aimed at a different technology and paper type altogether.

2. Open your graphic, still in RGB color mode with an appropriate color profile embedded. Make sure it’s exactly the way you want it to look, then make a copy, clearly identified, to keep in a safe place. You’ll need this master RGB version to prepare the graphic for online display, ebook editions, or even other printing setups. The following steps, like any conversion to CMYK, will irreversibly degrade the image, making it suitable only for print and only on certain presses. (But if you have only a CMYK version, do not first convert it to RGB, because that will only compound the damage! Just start with what you have.)

3. Use the “Convert to Profile” command to convert your graphic to the color space of the HP Indigo profile. Note that this conversion automatically changes the color mode to CMYK. You should not separately convert the graphic to CMYK to prepare for this step, because the graphic will in most cases wind up in the wrong color space.

4. Use the “Assign Profile” command to assign the profile for “U.S. Web Coated (SWOP) v.2,” Lightning’s prescribed CMYK color space. Alternatively, if your Color Settings already specify that profile for Working CMYK, you can just remove the HP Indigo color profile by choosing “Don’t Color Manage” for the graphic.

Your graphic will now print to the more appropriate color space, regardless of how Lightning handles it, and that should allow you to get more contrast and vibrancy. (Basically, you’re performing color management before the fact, but disguising it.) Note, though, that your graphic will probably look too dark on your computer display. You’ll have to ignore that!

The steps above are a sample workflow only. Using the same basic sequence of convert-then-assign, there are other ways to achieve the same result. For instance, you could keep all your graphics in RGB in your document and make the needed conversions on export to PDF and afterwards, with Acrobat Pro’s Convert Colors command. (If you apply that command to the entire document, make sure you "Preserve Black" to protect black type.)

With Lightning, if your graphic is meant for a book cover or is particularly ink-heavy, you may have additional work to do. See my article “Living Within Limits,” about Lightning’s restriction on Total Ink Limit, to figure if you need to adjust for that. But note that you must adjust the color space as described here before adjusting for the ink limit.

What about CreateSpace? The color space trick described above works there as well, but you don’t need it. All you have to do is submit your graphics in the Adobe RGB color space with profile embedded, and CreateSpace will manage the color correctly, apparently taking care of the ink limit as well. Just don’t try that with any other color profile, because it will most likely be ignored! This solution is much superior to the process I’ve described for Lightning, as it should adapt to any new POD technology that comes along, rather than making you go back to the book for new adjustments.

POD book covers may present an additional problem, because the plastic laminate can cause shifts in hue and brightness. Lightning’s glossy laminate, for example, tends to heighten reds, which can be a problem with skin tones. To adjust for this on one portrait photo, I used a setting of minus 20 Saturation in Photoshop’s Hue/Saturation command, with the menu set to “Reds”—though this proved too large an adjustment for another photo on the same cover. I haven’t noticed the same reddening with laminate from CreateSpace.

“Black-and-white” photos—or more accurately, grayscale—can also pose problems for POD publishers, often coming out lighter than intended. The problem is that most of us edit on computer displays with a mid-tone brightness adjustment of gamma 2.2, which is wrong for print preparation. So, the trick is to convert grayscale photos to the “Dot Gain 20%” color profile, or else the equivalent “Gray Gamma 1.8.” After that, you can either leave the profile embedded or else remove it, according to your workflow needs. If you remove it, the photos may look too dark on screen but will still print correctly. (Actually, how they print will often vary due to irregular toner supply on the press—but there’s nothing you can do about that!)

Please note that all the procedures I describe are meant to be performed within the context of a careful regimen of color management, starting with image capture and continuing through image editing, on equipment that accommodates your chosen color space. Otherwise, you may not get the color you expect. If all that is beyond you—and if color accuracy is crucial—I sincerely recommend you hire a professional to handle it, or else be prepared for a lot of trial and error.

Color work is not for the fainthearted!