I started glass etch about forty years ago using contact paper. In fact, went that route about four months ago for some entry doors for some people.
It's funny, I've talked to some remarkable artists who all but called me a liar for saying I use it. I tried to explain that I keep the pressure around 45 lbs, unless shading, when I drop to half that. They couldn't explain why I could do all but the heavy carving with it. Some people prefer not to learn, and assume today's technology always existed.
I keep about twenty or so rolls of various kinds of the stuff around for various uses [and the beige does work best for laying out lines].
I know my posts about sandblast glass etching, not wood carving would have mentioned the use of contact paper. I used beige or light green. Not white because the brightness will wear on your eyes.
Good to hear your success with contact paper.