Funny you should ask, I am planning to go by the paint store this afternoon to order some for a project that I am doing for my daughter. I'll let you know in a few weeks. Also check out:
You need to seal the patina or it will rub off with handling (think about what your hand looks like after picking up a rusty iron bar). You also need to use a sealer that won't affect the color of the patina.
I've done a lot of large turned projects using the Sculpt Nouveau type B metal coatings with various patinating agents. Good stuff. I like the bronze the best, but to each their own.
For pens I patinated the barrels and then cast it in PR to protect it from handling. Worked well, but I think a pen offers too small a canvas for this type of treatment.
