A rib is a flat, hand-held tool used to shape, smooth and compress clay. Ribs are made of wood, metal, rubber or plastic in many shapes, and are used on the wheel and in hand building.
What Is Rib?
On the wheel, a rib held against the outside of a pot while the inside hand supports it lets you refine the profile, remove slurry and thin the wall. Pressed across the base, it compresses the clay and helps prevent S-cracks. Rubber ribs are kind to soft clay, while stiffer metal and wooden ones give crisp lines.
In hand building, ribs smooth slabs and coil walls, blend seams, and compress edges so they are less likely to crack. Serrated metal ribs are used to scrape and even out surfaces, after which a smooth rib finishes them.
Most beginner tool kits include a wooden or metal rib, and many potters later add soft rubber ribs in a few shapes. Profile ribs, cut to a particular curve, help throw matching sets of bowls or mugs.
Look after metal ribs by drying them after use so they don’t rust, and keep wooden ones out of water when you aren’t using them so they don’t warp or split.
This pottery glossary entry from Le Studio Art Space is general educational content. Always follow the clay, glaze and kiln makers’ data for your own materials and equipment.