Plainsman Stoneware Clay - M340s $44.99 Sold Out This M340S is the same as M340 with added manganese to give a brown speckle in oxidation firing. This M340S is the same as M340 with added manganese to give a brown speckle in oxidation firing. Sold Out Added! You Might Also Like Plainsman Stoneware Clay - M390 $49.99 Laguna Max's Paper Clay $75.99 CCS Speckled Stoneware Clay $49.99 Mid Cal Grogless Stoneware Clay $49.99 Mid Smooth Stone Speck Stoneware Clay $49.99
