The major tools to make bobbin lace are a pillow, bobbins, pins and prickings. Materials required include multiple colours of yarn, standard needles, and "bobbins". Filaments are stretched and wound onto beams, cones, or bobbins ready for use. The roving (unspun thread) passes downwards from the bobbins to the draughting rollers. More complicated shuttles incorporate bobbins or pirns. When the bobbins on the spinning frames were full, the machinery stopped. Braiders can create complex braids up to 24 bobbins and incorporate beads. The rotors first used were wound as sixteen axial bobbins, one per pole. Many lace designs require dozens of bobbins at any one time. A will of 1493 by the Milanese Sforza family mentions lace created with twelve bobbins. Bobbins, which are traditionally made of wood or bone, are used to hold the thread. It is also used in artificial limbs, carriages and bobbins. Most hold between three and four bobbins. T-Top bobbins lose the distinctive square hole of the original PAF bobbins.