Polymer Clay: What It Is, FIMO or Cernit, and How to Bake It

Earrings shaped like tiny strawberries, pendants shaped like hamburgers, figurines, magnets—most of these are made from polymer clay. In this guide, you’ll find out what it is, how FIMO, Cernit, and Sculpey differ, which clay to choose as a beginner, and how to bake it correctly.

What Is Polymer Clay?

Polymer clay is PVC-based modeling clay. It stays pliable like modeling clay at room temperature and hardens only when heated in a regular kitchen oven. Once baked, it is firm, and the finished piece is permanent. It comes in dozens of shades, including metallic, pearl, translucent, and neon options. The colors can be mixed together, and finished pieces can be sanded, painted, and varnished.

It goes by several names: it is also called modeling clay or simply FIMO, and Sculpey in English-speaking countries. FIMO and Sculpey are brand names, not the name of the material.

FIMO, Cernit, or Sculpey: What’s the Difference?

FIMO is made by German company Staedtler. FIMO Soft is a soft clay sold in 57 g blocks divided into 8 sections, with more than 30 colors. It is compatible with the FIMO Effect, Leather-effect, and Professional lines. FIMO Effect adds metallic, neon, stone, glitter, and translucent options. Bake it at 110 °C for 30 minutes.

Cernit is a Belgian clay that is soft when warm and hardens as it cools. Cernit Number One is the opaque standard line; Translucent, Opaline, Metallic, and Pearl are effect lines, while Cernit Doll is made for dolls. Bake it at 110 to 130 °C for no more than 30 minutes.

Sculpey is an American brand. You won’t find it here, but tutorials on English-language websites also apply to FIMO and Cernit. A less expensive option to try is Rosa Talent Jam Clay 20 g.

Which Polymer Clay Should You Choose as a Beginner?

For your first pieces of jewelry, FIMO Soft or Cernit Number One in a small pack and two or three colors are enough. If you want more shades at once, choose the Cernit 12 × 25 g Basic set or Effects. For larger projects and dolls, larger packs are a better value: FIMO Soft 454 g or Cernit Number One 500 g.

How to Soften and Shape Polymer Clay

Knead the clay slowly in your hands until it becomes pliable. If it gets too soft, put it in the refrigerator for a while. Work on a clean, smooth surface. Light shades pick up dust and darker shades, so start with those. Shape it with a roller, blade, cutters, or molds; texture sheets add a pattern to the surface. Make holes for hanging before baking.

How to Bake Polymer Clay Properly

Place the finished piece on baking paper or a tile and bake according to the package instructions: FIMO for 30 minutes at 110 °C, Cernit for 20 to 30 minutes at 110 to 130 °C. Do not exceed the temperature or use a microwave. After baking, let the piece cool in the oven or on the surface. It will be fully firm only after it has cooled. Polymer clay pieces are not intended for direct contact with food.

How to Finish Your Piece

Once cool, you can sand the edges with fine-grit sandpaper and paint the piece with acrylic paints. A gloss or matte Cernit varnish gives it a gloss or matte finish; Cernit liquid gel is used to join pieces and transfer images.

Is Polymer Clay Safe for Kids?

The Cernit manufacturer recommends it for kids ages 8 and up; baking should always be done by an adult. For younger kids, air-dry clay, which hardens in the air, or modeling dough is a better choice.

Find the full selection in the polymer clay category. We compare all types of modeling clay on the modeling page.