Alternating torsion

A species-specific structure found in various tropical woods. It is created by a 1 to 8 cm wide layering of cells, which spiral around the stem axis in alternating directions. As the direction of the cell axis changes or crosses from layer to layer, radial gating produces areas of strips with differently oriented cells. This creates a changing reflection of the light, which produces an alternation of matt and shiny stripes. A disadvantage of alternating twist growth can be streaky resistance (tearing) and increased warping of thin side boards.

To obtain a soft surface on wood with interlocking grain, proceed as follows: First wet the surface with water so that the fibers stand up. Then allow the wood to dry and sand the surface with 80-grit sandpaper. If you want an even softer surface, you can then continue sanding with 120 grit sandpaper.