Black can be created by laying out multiple colors on top of
each other, so instead of pure black being used, your screen and printer will
register 100% black as an overlay first of CMY (cyan, magenta, and yellow) and
finally, it will process K (black) over top the blend. This creates a lighter
black resulting in transparency that is more like a dark gray when against
bright colors.
If you choose to stick with CMYK coloring when doing a
multi-color project including black, your best option from there is to create a
rich black. This is created by altering the CMY colors to create a darker mix.
The most common combination for a rich black that does not represent any other
color would be a 60-40-40-100 CMYK.
100% Black v. Rich Black
In order to see how your colors are blending, especially in
regards to any questions you have about a certain tone that appears, it is
important to preview your separations. By previewing the separations before you
print, you are able to view not only the blends that create your colors, but
also where there may be any overprint within your design.
Once it comes to printing out your separations, it is highly
recommended that you use RIP software. This will allow high-quality halftones
creating a smoother and more vibrant blend. When choosing the ink to best
represent your CMYK project, Union Tru-Tone Process Black will give you a
consistent and accurate color reproduction.