CMC is generic and refers to organic sodium carboxymethyl cellulose. The cellulose gum functions as a thickener, binder and suspending agent in glazes. Additions of 1.5% to any dry batch of glaze will make it brushable. Gums are used in ceramics to harden unfired ceramic glazes for safer handling of the ware. Mix with water to dissolve and age before adding to a liquid glaze. This is not food grade CMC. Please only use for ceramic purposes.