Quote Originally Posted by Les View Post
When contact printing in a Bostick-Sullivan frame using e.g. a 5x7 negative on 8x10 or 11x14 paper, what is the best way to obtain a white border with clean sharp corners?
You can cut a ruby-lith mask. Tape the neg. on top of the ruby lith with red masking tape. This will prevent light piping. and create a sharp edge with clean white borders.

The ruby lith isn't infallable though. If you have long exposure times the ruby-lith will leak UV light and cause the the coating to get enough exposure to create a dingy looking border.

I also tape the paper with painters tape to restrict the coated area to a minimum.

Hope this helps,