Quote Originally Posted by sanking
I mask off the area to be coated with 3" wide paper painter's tape. The tape realeases easily from the paper after the coating is brushed on.

I mask my negatives in such a way that a black border (or one the same color as the shadows of the print) about 0.2" wide is printed around the edges of the print.

I've used the method that Sandy describes too and it does work well. I will caution you not to press the tape adhesive down with a boning tool. I did this once and as a result when the tape was removed the paper came with it.