Mullers are used to grind pigment to a floury consistency, for mixing in a suitable oil or medium. In order for a pigment to colour the medium richly and evenly, it must be finely ground. This small glass muller from C Roberson has an ergonomic handle and is robust enough to survive extensive grinding. Available in 5cm, 7cm and 10cm sizes. Handmade in a heavy, hard glass. Ergonomically designed top. Well suited to extensive grinding of pigments.