AC Fir Plywood is a general use plywood. The Face veneer is a Douglas Fir, the Core veneer is western softwood and the Back Veneer is Douglas-Fir or Whitewood. The adhesive is exterior grade and water resistant. The Face is fully sanded. Use water based putty for repairs. Workability: Can be easily cut into almost any needed shape or size with commonly available tools. Relative lightness in weight: Ratio of structural performance to weight easily beats other products. Sanded veneer may contain patches to maintain an even surface.