Cat. Natur (according to PN-EN 13226: ○) : Wood with a dark color throughout the entire cross-section, with a relatively uniform color and various patterns. Sound knots up to 5 mm in diameter, rotten knots up to 1 mm are allowed. White is allowed on the left side and does not transfer to the wear layer. Surface and front cracks allowed up to 0.5 mm deep. Features resulting from the natural biological structure of wood, such as lycowood rays or gloss, are permissible. Properties not specified above in accordance with the Polish Standard No. PN-EN 13226:2009. Up to 3% of elements may have defects that do not meet the criteria of the declared class. In the case of slats with a finished or partially finished surface, edge runs are allowed in each class.
