I too have made a couple of foam insulation extensions for my machines....they turned out great. I covered them with duck cloth and then covered that with a heavy clear vinyl. Turned out real nice! I covered the foam-i because it was in storage and didn't come completely clean. On one of my foam-i extensions I put a paper ruler just to have at-the-ready and also a conversion chart from yds. to decimal measurements. So you can put any meaningful-to-you info under the clear vinyl.