Character: It is characterized by the sapwood and the knots, as well as its prominent textural and color variations. Flame pattern is permitted. Knot: 5 – 6 healthy and dark knots – even grouped ones – are permitted in each stripe, up to a diameter of 25 – 30 mm. Fallen-out knots are permitted, up to 30 mm in diameter when corrected by filling. Sapwood: Healthy sapwood is permitted up to the third of the slat width, even from both sides.
According to the EN 13489 standard, 3 % of a different grade than indicated is acceptable.