How to Stop Polymer Clay From Burning


Hi friends! I hope your Monday is going well…as well as a Monday can get, anyways.  On Friday I blogged about polymer clay for anyone who is unfamiliar with it (read it here if you missed it) and I ended the post warning you about scorching and darkening your clay during baking.  Well I’m here today to share with you some cool tips and secrets to making sure your precious clay pieces never burn again!

Temperature vs Time

The first thing to remember about polymer clay is that it cures based on two factors: oven temperature, and duration of cook time.  What’s special about curing polymer clay, however, is that these two elements are relative to each other. Meaning that if you increase the temperature you can decrease the time, and vice versa.

The recommended cook times for Sculpey clay is 275 F for 30min per 1/4″ thickness of clay.  So if you have a piece that is 1/2″ thick, you would cook it at 275F for an hour.  Unfortunately, however, depending on the colour of the clay (let’s say it’s a white pearl) cooking at that high of a temperature will no doubt darken the clay, and possibly even leave scorch marks on it.  Both are results we are NOT looking for.

So what’s the solution?  Instead of 275F, you could turn the temperature down to 250F and bake the piece longer, for about 2 1/2 hours instead of one.  The longer cook time will still cure the clay, but the lower heat will reduce the darkening of the clay’s colour.

Please note that you must ALWAYS know the real temps your oven reaches by using an oven thermometer. Don’t trust the temperature you set to be the true temperature inside the oven.

So we’ve handled the high temperature problem, but maybe our clay is still darkening too much.  How else can we prevent this?  Well, this leads us into the second tip…


If we protect out clay while it’s inside the oven from random hot spots and temperature spikes, we can further ensure that our piece will come out with brilliant colour.  There are a few methods that can be used here, and I actually use a combination…

Glass bowl  – using an oven-safe glass baking bowl to hold your clay piece will provide more separation from the heating elements in your oven, allowing the clay to receive a more even flow of heat.

Tenting – this is a popular method where aluminum foil is draped over the clay piece, insulating it from the oven.  One thing to keep in mind, however, is that if any of the aluminum foil touches the clay while it’s curing, it will leave that spot super shiny, and thus your piece will have an uneven finish to it.  I like to use a different method than tenting…

Small Particle Insulation – This is the method I use, coupled with a glass bowl and reduced temperature/longer cook time.  What you do is simply use cornstarch, baking powder, baking soda, or any other baking-friendly fine particle and completely cover your clay piece.  Put some in the bottom of the glass bowl, set your clay on top, then cover completely with the powder.  This provides a total insulation of your clay, making sure it receives even heat, protecting it from hot spots and thus scorching.


So there you have it…use a lower temperature with a longer cook time, a glass bowl,and baking powder.  Using these three secrets will ensure your clay always comes out looking perfect.

To see this method in action, watch for my tutorial coming out tomorrow!  We’re going to make a pretty peacock pendant together, and in the video I show you exactly how I bake my clay!  I hope to see you then, and have fun playing with your polymer clay!


Leave a Comment :)

  1. Ummm Ashley you put that you are supposed to bake the clay at 175 F but I am sitting here looking at a package of Sculpey Clay and it says 275 F, was the number you used a typo?