I print several designs to one sheet of overhead transparency made for my type of printer. The plastic sheets aren't cheap, but since I only do it once in a while it makes thing easier and a single package lasts me a very long time. If you have an inkjet printer you have to wait several minutes for the sheets to dry (the ink WILL get on fabric otherwise) but laser printer sheets are ready when they come out.

I use that as well. Transparency film is such a versatile tool. I had some left over from teaching a few classes and ended up using it in a few scrapbook projects so when I found a nice sized box on clearance I went ahead and grabbed it. Since then it seems like I have found endless uses for it.