Looking strong wood where they are allowed healthy knots. Resin pockets, slits, holes of nails, small pieces of other material (nails, ...) are permissible. Chamfering and mechanical damage are allowed. The irregular holes from natural wormhole and the different colors are a specific characteristic of this material. The slats are glued only on the soul. The long sides of the slats are not glued. Retro: Spruce aged not plastered or repaired, unpolished.