Thanks, Eliea. I have an older oven so I decided to stick with the toaster oven for even heating, otherwise I'd throw a cookie sheet full right in there. I wasn't sure if the shrinky dink paper gave off any smells, but so far so good
I used to use the oven but then I bought a heat tool that you can find in the scrapbooking section of craft stores and it works great. I just hold the piece down with a wooden dowel through the hole to keep it from blowing off the table. It's fun watching it shrink this way and you can make sure it's even better this way too (at least for me). When I did it in the oven I often had a problem of the shrinkys sticking to the cardboard I was cooking them on and so they were ruined.
Can you use a heat gun on polymer clay? I'm not sure if I should just go out and find a cheap toaster oven to do all my crafting or if I can keep using the same one for food and crafts.