How to Mix Polymer Clay


Many clayers find themselves with blocks of different types of clay from various product lines or completely different manufacturers. Sometimes, those blocks are perfect for mixing — but is that an option? You can absolutely mix different types of polymer clay together. If you do, you’ll just need to know a few things about the clay you’re working with. Understanding them can help you use the right temperature for curing the piece and make sure the mixture is smooth and easy to work with.

The Difference Between Sculpey Clay Types

Most Popular Sculpey Clay

Let’s start by exploring what makes different clay products unique. Some of our most popular Sculpey clays are:

  • Sculpey III®: This clay is soft and easy to condition, providing a matte finish. It works well for kids, beginners and general hobbyists and comes in a wide range of colors, including glitters and metallics. Sculpey III® is a good choice for home decor, and figurines.
  • Premo™: Premo™ clay holds crisp lines, doesn’t bleed and comes in specialty options such as metallics and glitters. It cures to a satin finish and is best for frequent clayers and professional artists. If we compare Sculpey Souffle vs. Premo™, Premo™ has the advantage of having the largest color selection, including deeply saturated hues, glitter, metallics, granites and fluorescents. You might use Premo™ in everything from jewelry and figurines to faux stones and mixed media.
  • Souffle: Another great option for frequent clayers and professional artists, the Souffle lineup is a strong, self-supporting clay designed not to crack, making it a good choice for large or lightweight pieces. It holds onto textures, clean lines and fine details and doesn’t drag when sliced. It cures to a suede-like finish and comes in fashion-forward colors, great for jewelry and home decor.

A common comparison is Sculpey III® vs. Premo™ and Sculpey Souffle. If we break it down, Sculpey III® has a baking temperature of 275°F (130°C) with a recommended baking time of 15 minutes per 1/4 inch (6 mm) of thickness. Premo™ and Sculpey Souffle, on the other hand, both have the same baking temperature of 275°F (130°C), but they differ from Sculpey III® in that they have a recommended bake time of 30 minutes per 1/4 inch (6 mm) of thickness. If you’re working with something else, check out our FAQ for other Sculpey product bake times.

These clays work well in different situations and can be mixed together, as we’ll discuss next, but you’ll need to keep their differing temperatures in mind.

Mixing Polymer Clay Types

Many new polymer clay crafters tend to be concerned about mixing clay. They may get quite nervous about the topic of mixing brands due to the baking times and temperatures recommended on their clay packaging. With varied baking times and temperatures, how can you mix them?

Combine two polymer clay types

If you’re looking to combine two colors, spend some time on this step and do it thoroughly. A chunky mix could lead to separation or cause the clay to form layers during curing. Instead, condition your clay well with a thorough kneading. Consider using a clay conditioning machine for the best results. If one of your clays is harder than the other, you could also add some clay softener and thinner to make it more malleable.

As a general rule of thumb for all brands, don’t bake at a temperature lower or higher than what’s listed on the packaging. If you bake lower, the clay in the center of your piece won’t have enough heat going into it to fully cure. The piece may seem baked on the outer layer, but the inside could be underbaked, meaning the clay will be brittle and most likely break at some point. At the other extreme, baking at a higher temperature than the one on the packaging could risk burning your clay.

The baking time, on the other hand, is different. Similarly to the lower temperature, if a piece is not baked long enough, the heat won’t have enough time or strength to reach the clay in the center, resulting in brittleness and breakage. But baking the clay to the recommended time or even longer ensures the clay is fully cured, which gives it strength. Baking it longer is generally fine, as it allows enough time to ensure everything bonds together.

If we compare the baking times of Souffle and Sculpey Premo™ vs. Sculpey III®, you’ll notice that Sculpey III® has a longer bake time. Premo™ and Sculpey Souffle need at least 30 minutes of baking time. Although Sculpey III® doesn’t need as long, the extra time doesn’t hurt it and will actually help strengthen it. If you’re baking a piece with a mixture of Sculpey III®, Premo™ and Sculpey Souffle, bake it at 275°F (130°C) for 30 minutes or longer. 

The photos in this post are of polymer clay charms made with a mixture of the brands mentioned. Some parts of the charms are custom colors mixed from the different brands, while others have sections made entirely of the varying brands. They were all baked at 275°F (130°C) for 30-60 minutes.

When mixing different clays, keep these overall tips in mind:

  • Use an oven thermometer to monitor the temperature. Don’t let it exceed the recommended temperature, and use the highest baking temperature listed for your clay varieties.
  • Polymer clay bakes from the outside to the center. Bake your clay long enough for the heat to reach the middle. Removing the clay from the oven too early can result in an underbaked and brittle piece.
  • Bake for the longest recommended time listed on the packages of the brands you’re mixing. Keeping your clay in longer ensures that all clays have enough time to fully bake through and gain strength.

Shop Our Products

Whether you’re aiming for the perfect color or you want to use up all that clay you have lying around, mixing clay brands is a great way to do so. It works well and can give you more options during crafting, especially when using the wide range of polymer clay products from Sculpey. Grab some clay from our store, or reach out to us with any questions about mixing Sculpey clay!

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