so basically you need to tape off in a circle on a flat surface...right? i dont have much painting experience, but i would imagine you could lay down a "block" of tape on an easy-to-peel-from surface like acrylic, draw the size circle you need on the tape, use an exacto to cut out the circle, lift it off the acrylic, and the transfer it to the surface to be painted. that way you would have the perfect circle of tape.

:shhh: i do cocaine :/shhh: