I found a local supplier of Valspar 2nd Skin spray on peel off rubber coating, same product that makes plasticoat, but this stuff is meant to be a spray on painting mask that peels off.
I have tried a couple different oramask products and I’m not personally a fan, it doesn’t always seem to adhere properly for me and the finer detail the carve the more little edges seem to peel up on me.
so my process was this,
I painted a pieces of scrap mishshapen MDF with acrylic black paint, then applied 4 coats of Shellac, let the final coat dry completely, then applied 4 coats of the 2nd skin, following the cans instructions to the letter for dry times. Let it dry over night. Then ran a test carve. small font, fine details, circles triangles etc.
I then sprayed the carved areas with enamel spray paint, let it dry a couple hours, then peeled off the rubber coating and along with it, all the over spray.
There were a couple areas that I cleaned up with mineral spirits, and then clear coated
The pics show that the lines between the black and pink are super clean, I’ve simply peeled up the rubber coating and gave it a quick wipe down.
(disclaimer: this worked for me in the method I described, If this process messes up your project, do your own research and test drive it yourself before using it on something of value.)