Armoire From the Hermitage Museum, Saint Petersburg, c. 1690
The technique of combining tortoiseshell with pewter, copper and brass was highly perfected by Boulle and sometimes (annoyingly) bears his name as a generic cataloguing term. The technique, called tarsia a incastro, requires placing sheets of the contrasting materials in a stack or packet (fastened temporarily together) in which the design is then cut using a special saw with a vertical steel wire, the bocfil.