Conditioning polymer clay before use is essential.  If not conditioned sufficiently, finished pieces will be brittle and break easily

Please note: KATO POLYCLAY and FIMO PROFESSIONAL are firmer clays and CANNOT BE CONDITIONED BY KNEADING. They are designed that way because once conditioned they are easier to work with than softer clays. The reason why many professional artists prefer these brands.

While it’s not incorrect to condition softer clay by kneading in the hands, when you begin working with larger quantities of clay, you will want a quicker method of conditioning as you can only knead a small amount at a time. Whether a soft or hard brand of clay, the following method (used by professional polymer clay artists) is recommended.


Conditioning with an Acrylic Roller:

  1. Cut a slice from the block of clay (either side depending on how much you wish to work with) approximately 6- 8mm thick. (Don’t worry if you can’t cut an even slice, neither can I). (Figure 1)
  2. Using an acrylic roller, roll until it is 2-3mm thick.(Figure 2)
  3. Slice in half with a blade. See tip a) below for how to release clay from the work surface. Note: The clay can be folded instead of slicing in half but as folding can trap air, we recommend begin by slicing.
  4. Stack one half of the clay on top of the other.
  5. Roll again to 2-3mm thick.
  6. You will need to slice, stack and roll 6 or more times until you can bend the clay without it cracking on the fold line, (Figure 4)

 Condition Polymer Clay.1

Roll even sized sheets Rolling evenly thick sheets with a pasta machine is easy. To roll even sheets using an acrylic roller, use the same number of cards (from a pack of cards) on each side of the sheet of clay. Many tutorials describe the thickness of clay for a project by “how many cards thick” the clay should be rolled. It is a universally used polymer clay measurement.

Atlas Pasta Machine 150 Wellness

As your polymer journey continues, a pasta machine for rolling clay will become a favourite piece of studio equipment. Then further on the journey, a machine added to the pasta machine (that rolls much faster than you can crank the handle) will become your best friend in the studio! Especially useful for those with hand health problems.


Conditioning with a Pasta Machine:

  1. Cut a slice from the block of clay (either side depending on how much you wish to work with) approximately 6- 8mm thick. (Don’t worry if you can’t cut an even slice, neither can I). (Figure 1)
  2. Using an acrylic roller, roll until it is almost thin enough to go through the thickest setting on the pasta machine. (Figure 2).
  3. Roll through the thickest setting on the pasta machine.
  4. Roll through the second thickest setting.
  5. Roll through the third thickest setting.
  6. Set back on the second thickest setting.
  7. Fold clay in half. Place the folded edge into the machine first.
  8. Set back onto the thickest setting.
  9. Roll, fold and roll again on the thickest setting. Always placing the folded edge first into the machine.
  10. Continue until the clay, when folded in half as in figure 4, has no cracks appearing down the fold line.


  1. Clay will stick to your work surface (tile, work mat, table etc). To release it, use a tissue blade – held on a 45O angle, pressing down towards the work surface, slide under the clay, dragging the blade towards you. Also use this method to release and lift clay to prevent distorting your cut shapes.
  2. A guide to how long you should condition for is to blend your own colour. Cut a slice from 2 different coloured clays. Condition using the method above, stacking the different colours one on the other.  When they become one colour with no streaks, the clay is conditioned. Plus it’s fun making your own colours!
  3. Some clays are drier than others, even fresh clay can be dry and crumbly if a piece is broken off instead of sliced off. This is particularly so with metallic clays as they are loaded with mica particles to give them their metallic or pearl effects.  As clay ages it can also become drier but this does not mean it is unusable.  The addition of one of the proprietary products listed below will make even the driest crumbly clay usable again:
  • Kato Liquid Medium (a liquid version of polymer clay), Work a little into the clay by conditioning with the liquid medium. If super crumbly, chop clay into tiny pieces and leave in a plastic zip lock bag with the Kato medium drizzled over it for a few days. Then work together until it can be rolled into a sheet. Messy but it works.
  • Sculpey Clay Softener (oil based). A few drops makes a big difference. Use the same way as Kato Liquid Medium (above).
  • Cernit Magic Mix (plasticizer). Use a little at a time – you can always add more. Use the same way as Kato Liquid Medium (above).
  • A little translucent clay mixed with a coloured clay has little effect on the colour but can help soften the texture. Translucent clay does not contain pigments, there is usually quite soft. Many like to mix a little white clay into strong coloured clays for a softer colour and white clay is often softer to work with also.
  • Polymer clay can also be too soft to work with. If this is the case, it can be leached to remove some of the oil.  Sit it between sheets of copy paper (with a book on it) for 10 minutes.  Some will require longer leaching, depending on how soft they are.  Alternatively leave out overnight, unwrapped but covered with a clean container to keep the dust off.
  • Partially baked clay (if left in a hot car) is seldom salvageable but still worth trying.

Working with the Clay:

To make a ball of clay from a sheet of clay, cut a circle, fold in half, pressing out air as you go. Fold in half again, continuing until it can no longer be folded in on itself. Then the clay can be rolled into a ball between the hands.  Tip: To make the same sized beads time after time use the same size cutter to cut the circle. The beads will all have the same amount of clay.  

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