Chalk

About

Artists' chalks were originally natural minerals cut into sticks: black chalk from carbon-rich shale, red chalk from clay coloured by iron oxide, and white chalk from calcite or similar soft stone. They glide across paper, can be sharpened for a fine line or rubbed for soft shading, and work fast, ideal for studies from life.

Italian draughtsmen of the late 15th and 16th centuries made chalk central to preparatory drawing. Michelangelo modelled muscular figure studies for the Sistine ceiling in red chalk, and Venetian artists often drew in black and white chalk on blue paper. The trois crayons technique, combining red, black and white on toned paper, was used by Peter Paul Rubens and brought to a peak in 18th-century France by Antoine Watteau and François Boucher. Look for grainy strokes catching on the paper's tooth and softly blended passages.