As I’ve progressed on my acrylic projects, I’ve gotten a lot of interest in making repeat pieces. Some as many as 40-50. The most time consuming part for me is the weeding process. Some of these designs are very intricate, we’re talking many hundreds of pieces 1/8" or smaller on a single piece.
Many of the suggestions here do not work when you’re talking about an engraved then painted piece, on that micro of a scale. Plastic razor blades are great at getting the pieces off, but wear down fast and actually scratch the surface. Tape leaves its own residue or simply removes the paint and leaves everything but the top layer of masking. Water still involves scraping and thus scratching.
I take pride in these pieces, and deliver them with virtually zero scratches or imperfections, which is a feat when you consider the scale (tiny details, many items, glue and welded layers, etc.). I just need to find a way to make weeding take less than 20-30 minutes per piece.
What gave me the thought of a light tack masking is my circuit boards. They come in different “stickiness” levels for different purposes. Since I’m just engraving and cutting, then immediately peeling, I really don’t think the level of tack these masking have on acrylic is all that necessary. I’m thinking if I take the time upfront to peel off the factory masking and apply something very lightly, I will hopefully have a much easier time getting it off. The entire reason I need the masking is for the hazing that happens when hot particles settle on the surface without masking.
I wish there was a spray on product that would just coat the surface to prevent hazing but be washable. That, or someone needs to invent truly water-soluble paper masking that is laser safe.
So, I can think of a couple ways to get extra light masking, but in the end the masking process is labor intensive no matter how you slice it. The nature of the beast.
Option 1 would be to buy light tack masking, then further de-tack it if necessary by repeatedly sticking it to a cotton cloth. Each time you peel it away from the cloth it’ll be a bit less tacky.
This is not a great option at scale for lots of reasons.
Option 2: make your own water soluable liquid mask. I’ve used wood glue as a mask before and it’s great. You’d want to thin it way down to work in a spray bottle but I bet it would work.
In theory you’d soak the final pieces in water and the glue would dissolve. Combine with an ultrasonic cleaner and I bet it’d work. You’d need to be sure your paint completely dried first but in theory… maybe?
Option 3: liquid masking is a thing in the art community. Surely there’s a water soluble option? My initial search didn’t yield any results. Hmm.
There has been much discussion of varieties of alcohol and additions to alcohol that can cause acrylic to shatter. However, if you test first it is excellent for dissolving adhesive so much that the masking just floats off. I have several decorations where I floated the masking off and then reapplied it to various tools like my magnifier handle.
A hand sanitizer does not attack the hands, then it will not attack plastic either, however, I did get some cheap industrial hand cleaner that did mess up acrylics.