Character: It is characterized by the sapwood and the knots, as well as its prominent textural and color variations. Flame pattern is permitted. Knot: Healthy, well intergrown knots in sizes of up to 15 mm Ø, and black knots in sizes of up to 5 mm Ø are permitted, also in groups. Sapwood: Healthy sapwood is permitted up to about the 1/3 of the lamella width.
According to the EN 13489 standard, 3 % of different grade than indicated is acceptable.