ChiaoGoo Patina Single Points have precisely tapered, hand-crafted tips. They are made of Moso bamboo which is the largest and strongest bamboo out of over 1,000 different species. The size is permanently laser imprinted on each needle and cap. The patina color is obtained with thermal heat. Sizes range from US1 (2.25 mm) all the way up to US50 (25 mm).