Clay

Clay is an amazing material that has been around for millions of years. When clay dries out, it is simply added to water and left to soak before being kneaded back to life. Mold is a natural part of all clays and makes it easier to work with. Potters have been adding organic substances to clay for centuries to promote mold as the clay ages. 

There are clays with more or less grog. Grog gives the clay structure and stability. The larger the object to be made, the more and/or coarser the grog the clay should contain. Clays with no grog or up to 20% with a maximum of 0.2 mm coarseness are chosen for throwing.