What type of surfaces should I bake clay on? A variety of firing surfaces can be used depending on your need. Some possibilities include: Bristol board, parchment, printer paper, glass, ceramic tile, non-stick baking sheet, cornstarch bed, polyester fiberfill bed, and polymer clay armatures for holding needles. Clay Baking Tip: The temperature at which paper catches fire is 451 degrees Fahrenheit. Glass has an even higher burn point. Our personal favorite baking surface when baking polymer clay is a silicone baking sheet for the following reasons. 1. They can be washed and used repeatedly. 2. Nothing sticks to them, so they are very easy to clean. 3. They provide even heat distribution. 4. There is less potential for burning.