I was going to paint my calipers as well. I have not tried it yet, but I believe that if you mask the MASERATI letters on the Caliper and cut between letters so that each letter has its own piece of tape on it, then press down on the letters so it stick well, you can bend the tape over the edges of the letters so that you can file or VERY paitently trim off the excess with a razor so that only the tops of the letters are covered with tape which is essentially a stencil. Then you can paint right over the caliper and peel the tape off later after it is all dry.
Theoretical of course, but it should work. High temp engine/header paint is a must and yes, get it real clean first.
good luck
Robb