How to Soften Sculpey and Fimo Polymer Clay

The older Sculpey and Fimo polymer clays get, the harder they become. Every so often I'll get some Fimo that I think has probably been floating around warehouses and craft stores for at least a decade before it reaches me—it's that hard and unmanageable. Also, the old hard clays do this weird thing where they try to break off into little annoying chunks, or crumbs, instead of forming together and kneading properly.

These ideas aren't strictly for unmanageable clay, either. Sometimes you just want a softer clay than normal to work with, either so it won't hurt your hands or so it'll bend more easily to the shapes you want. Here are some tips and ideas on how to soften Sculpey or how to soften Fimo.

Clay Softening Additive Products

First off, there is a product for this. We're not the only ones with this problem. Sculpey has a liquid softener sold beside the polymer clay blocks. You add a couple of drops to your clay, knead a while, and walla. If you work often with polymer clay, you might want to spring for it, though personally I find it a little expensive if you have a lot of hard clay. I tend to switch between using it for white clays and using oils for practice pieces or on dark colors where any discoloration won't be visible. Fimo also has a softening product, but it's a bit harder to find. It's a clay, not a liquid. Some people recommend kneading in a little transparent Fimo to soften Fimo clay, as well, though I haven't tried that.

Soften Clary with Household Items

Then there are these cheap and emergency options:

1. Whale on it — Keep it in the package or put it in a baggy, get a rolling pin, and beat it and roll it and go a bit nuts. Use lots of pressure. My favorite way is put it in a baggie, then put it in an old pillow case, and go outside swing it over your shoulder to beat it on the sidewalk. It's tiring, but it's more of a general strain than trying to use your fingers on little bits of hard clay. This will only get you so far, though.
2. A household oil — Be warned, this slightly discolors the clay (mostly noticeable for white) and can make it more brittle after cooking. That said, it works better than I expected. Baby oil seems a little better, but cooking oils like canola and vegetable also work. Add some (a teaspoon or less) and knead thoroughly. Add more if necessary.
3. Mix clays — Sculpey is softer than Fimo, in general, and sometimes you have a hard Sculpey clay and a soft Sculpey clay in the same color. Mixing two of the same or very similar colors will give you something harder than the soft, softer than the hard. If mixing Sculpey and Fimo, cook it at the higher temperature.