Pvc can be purchased in sheet form. I think your method will be cheaper. I can get 20 l.f. of 3" for 12$ at a plumbing supply. Box stores also sell pvc 1x6 that has to be planed for lithos.
I have played with it a little, but I have not gotten the results I would like. I don't know if it is a depth/height problem or what. I just have not had time to experiment.
Brent
A,B machines, PE,probe,conforming vectors, centerline, 2d,3d,stl and dfx imprt, rotary , 3.xx, Pattern Sculptor
OS X Yosemite
Woodwork is what I do to pay for my tool addiction.