A frit is a part of a glaze recipe that has been melted and reground for inclusion in the final glaze. This process will render otherwise soluble minerals insoluble, make harmless any substances which in its raw state may be injurious, remove volatiles, and generally give better control to the final glaze fusion. Frits can be used in any glaze and can also be used as fluxes in bodies, slips and engobes.