I tried the masking film I ordered from SignWarehouse on the 1/4" Birch Plywood and it mostly doesn't work. It's not tacky enough and as it melts it peels back away from the cut so the board still gets charred. It works where it sticks it just doesn't stick around the entire edge. Bummer... that was a waste of cash. Will have to find something else. [UPDATE] After a quick search on SawMillCreek forums I realized ordering plastic film as a mask was one of the least brilliant purchases I've made in a while. Don't know why I didn't think about it... I saw someone else recommend it on Thingiverse and just blindly ordered. Turns out plastic melts! Shocker. I've tried masking with blue painters tape before and it worked great. So now I need to source some PAPER transfer tape... or just buy a bunch of 3" blue painters tape. Hmm.