What is Rich Black?

Here are the values we use on offset presses for rich black.

100K - 60C - 40M - 40Y

--from the Scribus Archives

And some further advice:

For text below 12 points, I would advise not to use rich black with 4 inks.

You could use a 100K and C50 instead, if you really want it. But again, registration issues might occur with smaller typesize. Depending on the font and face you use. You'll be a better judge. I only point to the issues that might or will occur and I only want to explain a bit so you understand what's going on. You could also discuss this particular issue with your printer.

Louis Desjardins