Our exotic wood and ceramic ring core blanks are pre-channeled for easy inlaying; breakaway material means they are safe to wear every day. Available in 9-14 standard ring sizes, including 1/2 sizes. Ceramic Black/White, Bold/Thin choices. Bold ring is 8mm wide, groove is 4mm wide, available in 9-14 standard ring sizes, including 1/2 sizes. Slim is 4mm, groove is 2mm wide, available in 4-10 standard ring sizes, including 1/2 sizes. Easy to sand inlay; won't scratch ceramic. (Caution: Ceramic is hard, yet brittle; when using a metal mandrill, do not over-tighten.)