The following are some guidelines for black values in our InDesign plug-in and PDF to Book workflow:
We recommend using a mix of 60C,50M,50Y,100K for any content in which a rich black is desired. (This is best for areas of large ink coverage).
For a cooler black try 80C, 20M, 20Y, 100K. For a warmer black try 20C, 70M, 70Y, 100K.
For text it's best to use 0C, 0M, 0Y, 100K.
It's important to note that these are not precise measurements but rather basic recommendations on what our tests have shown to be the best mix of color for a good black.
We do not recommend using "Registration Black" (100% of all inks) as this most likely will lead to problems when printing the file.
For reverse text on a rich black background the smallest size we recommend is 6pt sans serif, 8pt serif, and 10 pt script.
Placing a large order or completing an important project? As always, we recommend you order and review a single Blurb-printed copy first. That way you can see how your colors and overall project look in print, and correct any potential issues in your content or layout, before placing the final order.