Fillers are an indispensable component of architectural paints. They are ground natural rocks (minerals), but may also take the form of synthetic powdered ingredients or suspensions. Fillers are usually inorganic, crystalline substances (e.g. calcite, cristobalite), although some types of paints are also formulated with amorphous fillers (e.g. amorphous diatomaceous earth), and others, with organic fillers (e.g. synthetic polymer-based microspheres). Fillers are not pigments and so they usually have a low refractive index and are used to give the paint bulk, lower the cost of production, impart high-performance properties, such as reduced mudcracking (e.g. talc), increased resistance to wet scrubbing (e.g. ...