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Polymer Clay 101: Conditioning, Rolling, and Marbleizing Clay

Learn the basics of preparing clay, mixing colors, and making shapes. 



Polymer clays: unless otherwise specified, all polymer clays are by Sculpey (Premo, Sculpey III, and Studio by Sculpey) from

Pictured: Sculpey III polymer clay in Sunset and White. Premo polymer clay in Alizarin Crimson

Clay-conditioning machine, $25, by Sculpey,



  • Polymer clay
  • Clay-conditioning machine


  1. Step 1

    Conditioning: Polymer clay must be softened to prevent cracking and breakage. Knead it in your hands, and then run it through a conditioning maching (about $25 at craft stores). This tool makes the clay pliable, presses consistently flat sheets of various thicknesses, and blends colors. 

  2. Step 2

    To blend, form 2 or 3 rolls of clay and twist together (experiment with different sizes and color combinations). 

  3. Step 3

    Flatten roll by hand, and then run it through the conditioning machine. 

  4. Step 4

    Use flattened pieces for a stripy look, or roll it up and run it through the machine again for a marbleized effect.