Ribs are made of food-grade, rust resistant stainless steel. They do not flex.
Rib measures approx. 5 1/4" tall by 4 1/2" wide.
For a 10-12 oz goblets, use 1 lb of clay. Throw a 6 1/2" tall, 3 3/4" wide cylinder. Also try Lucile XL as a bowl, mug, or planter profile rib.