Tips & Techniques


Polymer clay pieces may be cured in a standard oven or in a toaster oven. When curing pieces, it is recommended that you test the temperature of your oven (especially when using a toaster oven) with an oven thermometer. To do this, place the thermometer into the oven in the approximate location where you will be curing your piece; wait for the thermometer to adjust then adjust the temperature of your oven accordingly until the appropriate temperature is achieved.


Kato Polyclay should be cured at about 300°F (150°C), however it can be cured within the range of 275°F (135°C) and 325°F (165°C). It has been approved to be cured at 350°F (175°C). You should never exceed a temperature of 365°F (185°C) when curing Kato Polyclay. When cured at elevated temperatures, Kato Polyclay will become harder and stronger, and have an increased surface gloss.


It is recommended that you cure your piece for 10-30 minutes. For optimal strength, it is recommended that you cure your piece for 30 minutes. Curing Kato Polyclay for longer periods of time will yeild similar results as curing it at elevated temperatures, however it is not recommended that you cure it for longer than the recommended time.

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Kato Polyclay, package instructions are sufficient for producing perfect projects of any size. However, larger projects that are cured at higher temperatures and for an extended amount of time, will sometimes display surface flaws. This is especially true when using translucent clay.


As an alternative to the package instructions, we recommend using a bed of baking soda to protect your project. This will allow an additional 5 minutes of baking time. The baking soda method is a reliable and simple way to insure that you do not experience surface cracks or imperfections.


In order to perform the baking soda method, you will need an oven, an oven thermometer (strongly recommended), a timer (or a clock), a ceramic tile, a disposable aluminum pan deep enough to bury your project, baking soda, and your Kato Polyclay project.


After creating your project and collecting your materials, follow these simple steps to ensure your project has a uniform surface.

  1. Preheat your oven to 300°F (150°C) and place your ceramic tile and thermometer in the center of your oven. After 5 minutes check your thermometer and compare it to the oven dial. If your thermometer reads a different temperature, readjust oven dial until your thermometer reads 300°F (150°C).
  2. Pour the baking soda into your aluminum pan until there’s enough to cover your project.
  3. Place your piece into the bed of baking soda. Make sure there is baking soda between the bottom of your project and the bottom of the tray. Use a spoon to cover your piece completely.
  4. Move the aluminum pan into the preheated oven and start timer. Bake piece for 10-30 minutes
  5. After baking is done, remove the pan from the oven and allow your piece to cool in the pan for about 30 minutes.
  6. After your project has cooled, remove your piece, rinse off extra baking soda with water, and dry it with a towel.
  7. You now have a perfect piece with a uniform surface. Your project is ready to be sanded, polished, finished, or simply used as is.



Some projects may require that you cure a piece multiple times. For example, after adding an uncured piece of clay or other medium to it. When you create a project like this, it is a good idea to cure the piece in shorter increments of time. For example, if you were baking a piece 3 different times, it’s recommended that you cure the piece for 10 minutes the first two times and 30 minutes for the final curing. This will save you time and insure that your piece is permanent.