Flaxboard, is an engineered panel material in which shives from the stalk of the flax plant are bonded together with a synthetic resin adhesive. Flax shives are in fact a by-product of the linen industry. Flaxboard is defined as a particleboard in BS EN 309 and is specified in BS EN 15197 Wood-based panels. Flaxboards. Specifications as containing at least 70% flax and can also contain other raw materials such as particles of wood.