5 cm (2 in.) diameter at base
Dimensions may vary with each muller.
Rublev Colours glass mullers are handmade by glass craftsmen. The bulbous handle is specially formed to provide a comfortable grip. The bottom of the glass muller is flat and sandblasted to provide an excellent grinding surface.
Use the muller on a slab of marble or granite (ideally porphyry) or a thick sheet of glass to grind and disperse pigments and other materials into paint medium. To use the muller on a grinding surface, it must first be prepared by sandblasting or roughing the surface with 100 grit silicon carbide. Both surfaces of the muller and the grinding slab should be retextured periodically after use. To disperse pigments in paint medium, place a small quantity of powdered pigment on the grinding surface and work in oil or water a little at a time with a spatula until a stiff paste is formed. Begin grinding the paste in circular or figure 8 motions until the paste has a smooth consistency. It is not necessary to bear down with your weight on the muller since the idea here is to disperse rather than to grind the pigment.