Ribs are made of food-grade, rust resistant stainless steel. They do not flex.
Rib measures approx. 5 3/4" tall by 4 5/8" wide.
For an 18 oz bowl, use 2lbs of clay. Throw a 5 1/4" tall, 5 3/4" wide cylinder. Also try Chloe as a goblet stem, cappuccino, or mug profile rib.