How to Bake Polymer Clay

Steps

1. 1. Place an Oven Thermometer Inside

   Before you turn anything on, slide an oven thermometer onto the middle rack. Cheap kitchen thermometers cost ten or fifteen dollars and they're the only honest way to know what temperature your oven is actually running.

   Tip: Leave the thermometer in the oven permanently. You'll calibrate against it every time you bake, and it doesn't get in the way of cooking food either.

   

2. 2. Preheat to the Packet Temperature

   Read the temperature on your specific clay packet - different brands run from about 110°C up to 140°C. Set the oven dial accordingly and let it preheat fully before putting any clay in.

   Tip: Different clay brands have different sweet spots. Sculpey Premo bakes at 130°C, Fimo Professional at 110°C, Cernit at 130°C. Check the packet every time you change brands.

   

3. 3. Lay Pieces on a Ceramic Tile

   Polymer clay needs an even surface that conducts heat smoothly. A glossy ceramic tile from any hardware store works best - the glaze keeps clay from sticking and the mass holds heat steady.

   Tip: Run a few white tester pieces the first time you use a new oven.

   

4. 4. Close the Oven and Bake at Least 30 Minutes

   Set a timer for 30 minutes minimum. Polymer clay needs that full window for the plasticizers to fully cure - cutting it short to 15 or 20 minutes is the most common reason pieces come out brittle.

   Tip: You can bake polymer clay multiple times. Add details, bake again, sand it, bake again - it doesn't degrade with multiple cures as long as the temperature stays correct.

   

5. 5. Test the Cure With the Bend Test

   Pull pieces out and let them cool to room temperature - clay is fragile while it's still warm. Once cool, pick a thin piece and try to flex it gently between your fingers.

   Tip: If pieces are brittle even when temperature and time are right, the issue may be the clay itself. Sculpey III is a modeling clay - too soft for jewelry.