I came up with this idea when I was curing some clay in the over and figured I might as well use some of the shrinking plastic that I had as well. Then I realized that I could combine the two things and have a great way to use up my shrinking plastic scraps.
The plastic should be shrunk first and then bonded with the clay. When the clay is cured with the plastic it will set and since the clay is baked at a lower temperature than the shrinking plastic was, there should be no problems.
This is a really fun idea and results in a very nice end product without the need for too much artistic skill. You can experiment with different colors of "leading" and could even try making designs or 3D objects like votive holders or trinket boxes.
-shrinking plastic scraps
Step 2: Color & Shrink
The "stained glass" I made was a abstract design to test my idea but if you wanted to make a specific design then I recommend cutting, coloring, and fitting together all the pieces before you shrink them.
Shrink the plastic according to the manufacturer's specifications. Make sure that the plastic is completely done shrinking before taking it out of the oven. If the plastic isn't shrunk all the way then it may shrink more when you bake it the second time with the clay which will result in gaps.
Push the plastic into the clay a bit to make sure it is in there nice and good. After you wrap the first piece you can smoosh other pieces of the plastic into the "leading" and start wrapping those too.