 In addition to the grain, quartersawn wood (particularly oak) will also often display a pattern of medullary rays, seen as subtle wavy ribbon-like patterns across the straight grain.Medullary rays grow in a radial fashion in the living tree, so while flat-sawing would cut across the rays, quarter-sawing puts them on the face of the board.This ray pattern has made quartersawn wood especially desirable for furniture and decorative panelling.