(b Paris, 1736; d Saint-Mandé, nr Paris, Oct 20, 1793).
French engraver and publisher. He came from a family of artisans and owed his training in engraving to his brother-in-law, the engraver Louis Legrand (1723–1808). Through Legrand, Bonnet became the pupil of Jean-Charles François in 1756, a year before the latter discovered the Crayon manner technique of engraving, designed to reproduce the effect of a coloured-chalk drawing. Around the end of 1757 Bonnet used the new technique to engrave a Cupid (see Hérold, no. 2A) after François Eisen. Gilles Demarteau, a rival of Jean-Charles François, enticed Bonnet to join his workshop and learnt the technique from him.
Bonnet engraved some 15 plates for Demarteau, and in 1760 he set up his own shop. During this period he strove to perfect the crayon manner by producing prints using several different plates, each inked with a different colour. Initially, he tried to reproduce drawings executed in black and white chalk on blue or buff paper; to do this he had to make a white ink that would not yellow with age. He was the first to use points of reference to print several plates one on top of the other. In ...