I finally got to play with PurEtch, a photopolymer etch resist film sold by Cape Fear Press.

It’s easy to use and uses no toxic chemicals: laminate it to your copper/other metal plate under “bug light” (the process is similar to applying sun-shade film to a window), dry it with a hair-drier, attach your transparency artwork, expose to sunlight (about 12-16 seconds at noon), then wash out the shadowed part with soda ash/washing soda solution and etch (see Cape Fear Press site for videos).

Instead of electro-etch, I use H2O2/muriatic acid at 2:1.

First impressions:

1. I’m still not up to the repeatability I’ve achieved with toner-transfer.
2. I think I’ll like this stuff once I get the hang of it.

The two recurrent problems I have (besides working hurriedly to keep cats/dog/family from flipping the lights on in the kitchen) are heating the plates/resist long enough to get the water out (I ruined first plate by over-heating), and leaving it to develop fully (I keep pulling it out early, then battling a transparent residual mask).

I’m sure this will get better as I gain familiarity/confidence with the new resist.