Rib (Side) — Lutherie Encyclopedia

Rib (Side)Type: glossaryThe thin, bent wood panels forming the sides of an acoustic instrument, connecting the top to the back.## Definition The ribs, commonly called the sides on a guitar, are the thin strips of hardwood that form the curved walls of an acoustic instrument's body, connecting the top plate to the back plate. Ribs are typically 1.5mm to 2.5mm thick and are bent to conform to the body's outline using heat and moisture. Common rib woods include rosewood, mahogany, maple, and walnut, chosen for their bending properties, appearance, and tonal contribution. While the soundboard is the primary tone-producing surface, the ribs play an important role by containing the air volume of the body cavity and reflecting sound energy back toward the top and sound hole. The rib wood species, thickness, and stiffness can subtly influence the instrument's tonal character, though this effect is modest compared to the soundboard. ## In Practice Bending ribs is one of the more dramatic processes in guitar building. The luthier heats the thin wood strip using a heated bending iron, a bending machine with a heated form, or a hot pipe, while applying moisture to prevent cracking. The softened wood is gradually persuaded into the curves of the body shape, requiring patience and experience to avoid splitting or scorching. After bending, the ribs are placed into a mold that holds the exact body shape while the neck block, end block, and kerfing are installed. The ribs must be dimensionally accurate and symmetrical, as any twist or deviation will carry through to the finished instrument. Some builders use laminat…