Corner and end blocks are fit into the rib mold. These blocks are the main structures that link the ribs, top, back, and neck together, and give strength to the finished instrument. Each instrument has a neck block, end block, and four corner blocks.

After the blocks are fit into the mold, they are carefully shaped with chisels and gouges. The shape of the corner and end blocks is important because it determines the shape of the ribs themselves. After the ribs are complete, the mold will be removed, but the blocks will remain attached to the ribs.

Ribs are shaped using heat, moisture, and gentle pressure to bend the thin wood. Ribs must be thin but strong. Ribs that are too thick and heavy will dampen an instrument’s resonance. The ribs’ curvature imparts structural strength, but they remain the instrument’s most delicate part. When they have been bent into their final shape, the ribs are attached to the blocks, perfectly fitting them around the mold.