A species-specific structure found in various tropical woods. It is formed by a 1 to 8 cm wide layering of cells that spirals in alternating directions around the trunk axis. Since the direction of the cell axis changes or crosses from layer to layer, areas of strips with cells directed in different directions are created with radial incision. This creates a changing reflection of the light, which causes an alternation of matt and shiny stripes. The interlocked grain can have a disadvantageous effect due to streaky shavings (tearing out) and more warping of thin side boards.