Viols with a shaped back
Bass viola da gamba by Claude Boivin (Paris, ca. 1740)
Bass viola da gamba, Cremona, ca. 1700 (lost likely: Pietro Guarneri of Mantova)
Although most have flat backs, some viols were made with rounded or curved backs, these being carved out of a thick plank of wood – like those of the violin or the violoncello. Contrary to common opinion, viols with rounded backs were made throughout the history of viol making, from the Renaissance to the Classical Period. Among the makers subscribing to this technique were: the Stradivaris, the Amatis, the Guarneri, the Ruggieris (Cremona), Joachim Tielke, (Germany), Barak Norman (England), Boivin, Salomon, Castagneri (France).