 Usually faced with hardwood, including ash, oak, red oak, birch, maple, mahogany, Philippine mahogany (often called lauan, luan or meranti and having no relation to true mahogany), rosewood, teak and a large number of other hardwoods.Flexible plywood is designed for making curved parts, a practice which dates back to the 1850s in furniture making.Aircraft grade plywood, often Baltic birch, is made from three or more plies of birch, as thin as thick in total, and is extremely strong and light.