Have you ever noticed that your big black areas look fine on your computer but prints gray when you send it to your printer? It is always important to remember that RGB and CMYK work completely differently. This problem can be resolved by building a “Rich Black” for your large black areas.
Rather than printing in 100% Black in these areas, try “Rich Black”, which is a printing term than means to create a black color built from 60% Cyan, 40% Magenta, 30% Yellow and 100% black.
Doing this in your large black areas will beef up your black to look rich and deep, like black should look.
Warning: Even though this trick works great for large black areas, this does not work for you text. Standard sized text printing in black should always be 100% black only.
Otherwise you are creating a registration nightmare for your printer often causing your type too luck fuzzy with the other colors hanging out (like you’re wearing 3-D glasses when you see it).