This is a post about customer files which seem so simple nothing could wrong, until someone like me says "your file looks great, but you have CMYK black". Customers typically respond in two ways: 'That's just not possible, it looks fine onscreen' or, 'What difference could it possibly make...leave me alone'. It's not that we enjoy nagging...it's an issue worth looking in to.
Files born in RGB (Red/Green/Blue), such as Publisher, PowerPoint, or even venerable PhotoShop (in RGB mode), do not formulate black as a discrete color. To show you "black" onscreen, (their usual target), they display 0-Red, 0-Green, 0-Blue. The absence of all three colors which drive your monitor appears as black. The problem is that we can't print from RGB, and the translation from RGB "black" to the printer's CMYK color model is faulty.
Because life is inherently unpredictable, RGB "black" translates into CMYK of approximately 75-Cyan, 68-Magenta, 67-Yellow, and 90-Black. Onscreen it may look fine, but from a printer's point of view there is not enough black, and too much of everything else. If we print all four colors as is, (full color printing), any type in that color has to be in perfect register or it begins to look like a 3-D comic book, as in the image below (click to see full size, and imagine a whole page of copy looking like this). In addition, there is something like 300% ink coverage, most of which is doing nothing more that making the drying time unpredictable.
On the other hand, if we're printing just black, and pull that color alone from the file, we get a 90% tint, which appears gray, as in this image:
What to do?
First, learn to think in CMYK and how to initiate your files in that color model, which, in simplest terms, means selecting CMYK as your working space for the project and choosing black as a discrete color. Second, learn how to spot check your PDF's before sending them off to the printer. The easiest way to accomplish the latter is "Output Preview" in Adobe Acrobat (not Reader, alas, the full-fledged Pro versions). The Menu sequence, in Windows, is Advanced>Print Production>Output Preview. It'll look something like this, and you can move the cursor anywhere on the page reading the values directly in the panel:
Another snazzy feature is the ability to see any stray spot colors, (or intentional ones), and turn off various colors to verify what is made of what. Maybe I'm a nerd, but I have this feature on a shortcut.
Sometimes it's useful to define a "Rich Black" swatch in your document, which can overcome the tendency of even 100% black to appear gray when the coverage is extensive. Here at our shop we find that 100% Black and 25% Cyan makes the most efficient rich black; it renders a smooth, uniform, dark black without excessive coverage. (Adding the other process colors doesn't seem to enhance the depth, and, in fact, tends to go brown.) We still recommend staying away from type with this swatch, however, unless the point size is considerable.
This topic is esoteric, I know, but the issue comes up once or twice a week, and sometimes causes a major headache. At the very least: the more you think in CMYK the fewer your surprises. Whether the issue is CMYK black, blues that shift to purple, or solid colors which print dark, Output Preview is an included feature which will teach you something each time you use it. Unlike your monitor, the numbers don't lie.
Wishing everyone only pleasant surprises when you see your colors in print!
Hugh Butler
Your Friend in the Printing Business
