 At thick, mahogany three-ply "wiggle board" or "bendy board" come in sheets with a very thin cross-grain central ply and two thicker exterior plies, either long grain on the sheet, or cross grain.Wiggle board is often glued together in two layers once it is formed into the desired curve, so that the final shape will be stiff and resist movement.Often, decorative wood veneers are added as a surface layer.