Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

I have been using tracing paper (Vellum?) and a laser printer to produce
transparencies for photoresist. I have some good results, but the large
dark areas tend to be less than opaque having a speckled appearance
which tends to be reproduced on the copper. I was reading about some
spray cans which supposedly darkens the toner pattern (Toner Aide and
Casey's toner darkener). Unfortunately I can't find a supplier in New
Zealand and if I could it would probably be around $30-$40 a can.
However they appear (from their MSDS sheets) to be a mixture of solvents
sprayed from a can so I mixed some Acetone and Ethyl Acetate and sprayed
this on the transparency from a small mister spray bottle I had. It
worked, although the vellum curled up a little.