A common question from clayers and crafters is what to do about polymer clay that’s become too hard. Can clay become too firm to the point where it’s unusable? The answer is yes and no. Fortunately, there are several methods you can use to soften polymer clay that has become too hard. 

Sometimes, you can store polymer clay for years and it’s still supple when you pull it out. If stored properly, polymer clay will last a reasonably long time. Because of the nuanced nature of clay and the variety of factors that can cause it to stiffen, we’ve put together some tips and tricks on how to soften hard polymer clay.

Three Ways to Soften Hard Polymer Clay 

Maybe you’ve opened a box of old polymer clay and find that it’s stiff as a rock. Or, perhaps your clay is just slightly hard and crumbly. Can you soften hard polymer clay? The answer is yes! There are many strategies you can use depending on how hard the clay has become. Here’s a few tips:

1. Give It a Squeeze

To determine just how hard your polymer clay is, try the squish test. Pick up your clay and give it a hard squeeze. With workable clay, even if it’s a bit cold, you should at least be able to round off the corners and edges with minimal effort. If you cannot round off the corners, or the block of clay isn’t squeezable in the slightest, then it’s too hard and needs to be softened. 

2. Use a Mallet or Neverknead Tool

This technique works well to soften polymer clay that is just a bit firm. Simply place the clay inside a plastic bag and smash it until it starts to move. A NeverKnead tool is akin to a mallet and has been designed explicitly for conditioning clay.

3. Mix It with Softer Clay

If you still feel your clay is too stiff, mix it with a section of clay that’s softer or fresher. 

How to Soften Old Polymer Clay

Polymer clay that is too old can adopt a rock-like consistency that makes it impossible to work with — at first. Warm up the clay by smashing it with a mallet or NeverKnead tool like you would with clay that’s too firm. Next, try crumbling the clay into a food processor and adding different plasticizers little by little.

Try each of these plasticizers one at a time until you get one to work:

  • -Baby oil or mineral oil
  • -Sculpey® clay softener
  • -A few drops of Translucent Liquid Sculpey® polymer clay
  • -Any form of translucent clay

If you find that your polymer clay is not absorbing any of the plasticizers, it may be partially cured. This can happen if the clay is exposed to temperatures that are too high for extended periods of time.

Make Sculpey® Your One-Stop Shop for Polymer Clay

We offer the highest quality polymer clay on the market. If stored properly, Sculpey® clay will last and remain workable for all your future crafts. Order polymer clay online today!