Oriented strand board, oriented scale panel: panels made of many not well-defined layers (on the contrary of plywoods). We could define them "woodflakes", which means long and thin wood shavings called "strandt", tied by a binder. The panel structure is thought in order to make it remarkably one-way resistant. That's why the scales of the outer layers run parallel to one of the two layers of the panel. Particular attention is dedicated to the dimensional relationship of the scales where the longitudinal dimension usually prevales on the transversal one, in a ratio of 10:1.This improves the one way flexion resistance.