The rim is the body of the banjo and supports the neck, tone ring, flange, and resonator.
Between 1925-1944, Gibson made its rims from three plies of laminated maple. Each ply was soaked and steamed so it could be bent. The end of each ply was tapered so it would overlap the adjoining ply, and then the plies were glued together using hide glue. The inner diameter of most one-piece flange banjo rims is 9.5″. The top of the rim (tone ring side) is 3/4″ thick, and the bottom is machined down to 5/8″ to allow the flange to slide onto the rim.
One way that Gibson identified its banjos was by putting a label on the inside of the rim. Before Gibson incorporated in 1925, they were the Gibson Mandolin-Guitar Company and the label used during this time carries that name. After incorporation, they introduced a new label that included their new name and some small wording changes. Higher end non-Mastertone models carried a simplified sticker (known as a “football” label), and cheaper models had no label at all.