I've used a few different masks based on the desired outcome but haven't decided on my favorite. I've used self adheisive laminating film, white glue, blue painter's tape, clear packing tape and duct tape. What have you used and what do you like?
Hope this goes in the right place - haven't posted in a while...
Anyways - have had very good luck with powdered RIT dye and fingernail polish remover (w/ acetone in it) --- not as dangerous and doesn't smell nearly as bad...
Pro, Star, Champion plastic work the best, in that order. Have had no luck with DX at all.
Have found that to get some really cool stuff dyed into a disc, get clear / opaque Champion plastic - a printout of the design and a butter tub --- Place the printout on top of the tub, then place the disc on top of both. With a toothpick and white glue, mask what you don't want dyed... and go from there.
The pictures on my profile however, were done with liquid RIT, which is hit or miss. (black turns out purple or gray) -- More pics coming.
I have been using sign vinyl for the actual stencil and contact paper for the rest of the disc to save on $. The problem I've been having recently is that if I don't have my mask at least 2 layers thick, the dye will bleed right through...even the vinyl!