With natural swirls and figuring, white mother-of-pearl is a favorite inlay material. Available straight or curved, each package contains enough random-length pieces for 15" of purfling.
These purflings can be squared and mitered with a file. For gradual curves without noticeable joints, fit straight purflings into the glue-filled channel and break them to conform to the curve. Using this method, the 125mm-diameter curved pieces will also fit slightly larger or smaller curved channels. The charts below show how much purfling is needed for Dreadnought and Triple-O style guitars.