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. The skill necessary to create the intricate scrolling patterns through the materials of highly different densities and strengths in this manner is quite extraordinary. Once the designs have been cut into the packet, it is disassembled and the cabinet maker has created two versions of the same design, the positive and negative, which he veneers onto the carcass. The first called en partie, presents the design in lighter colored metals on a background of darker tortoiseshell. The second, en contre-partie, depicts the designs in dark tortoiseshell on the light metal background. The metals are also engraved with additional decoration to create relief. The rectangular panels containing the hinges above and below the floral marquetry of the Hermitage armoire are executed en partie.