I have made several rotary pvc carvings on my rotary jig yet never made a flat lithophane because I was never able to find a cheap and easy source of Corian. I saw online somewhere a video of someone flattening pvc pipe to make useful things out of it so I had to try flattening it to carve litho's.

It was quite easy and got pretty good results. I just cut off an 11 inch piece of 3 inch diameter pipe then sliced it lengthwise. Then I popped it into the oven on a cookie sheet at 300 for about 5 minutes until it got soft. I pulled it out and put it between two 1x12 pieces and clamped it about half an hour until I was pretty sure it had cooled enough. The result was a perfectly flat sheet of pvc about 10x11. I carves a picture and it turned out as a pretty decent litho. I need to experiment some more but it seems like a much cheaper alternative to Corian.

Dave