Nifty trick...
 

I was painting my S/G that I am rebuilding tonight and was looking at the pulley. Every-time I have painted a pulley either I get paint all on the inside or I don't get the outer band covered. I don't like paint on the inside because as it wears it gums the belt up and sometimes slip and squeal. Trying to figure a solution I saw a roll of Teflon tape on the counter and realized its nearly the same width as the pulley so I wrapped and wrapped and wrapped the entire fifty cent roll and shot the paint too it. Just pulled it off and its perfect no paint inside, and a nice cut line all the way around that will be pretty close to even with the belt. I like it a lot and may share a pic tomorrow sometime.

Why didn't you just use a piece of an old belt?

As I said it was in a pinch, the nice part about it is that teflon tape needs nothing but a little bit of pressure and it stays put.