Throughout the history of violinmaking, different technologies for assembling the body have evolved. In Italy, instruments were built almost exclusively on an inner mold. Such a mold makes it easier to glue together the parts that define the outline of the rib frame, and thus of the belly and back. First, the top and bottom blocks and the four corner blocks are temporarily glued to the mold. Next, the ribs are bent by applying heat and are then glued to the blocks. Now, the final outline of the instrument is finished and can be transferred to the still unfinished belly and back. The mold is removed before the belly and back are permanently glued to the rib structure. Several molds from Stradivari’s workshop have been preserved to this day. They help attribute many of Stradivari’s instruments to body models.