Fumed silica, a colloidal form of silica which has an extremely small particle size coupled with an enormous surface area, is of use to the conservator who is formulating adhesives for use with ceramics. The addition of a small amount of fumed silica (3-10% by weight) dramatically alters the mobility, plasticity, viscosity, cohesive strength, and bond strength of an ad hesive. However, it is a difficult material to handle and most formulations must be determined empirically. See also AATA 21-1334 for entire proceedings.