ASTM D1006/D1006M-21 Standard Practice for External exposure testing of hand-painted and factory-painted wood and wood composites specifies a standard method for external exposure testing of wood and wood composite coatings. This standard is applicable to evaluate the durability of coatings under different environmental conditions, including the effects of UV, moisture, temperature changes, etc. under natural or accelerated aging conditions. Testing can be applied to hand-painted and factory-pre-coated wood and its composites to determine the adhesion, weathering resistance, disbonding resistance, and other performance of coatings. The practice provides researchers, manufacturers, and coatings suppliers with a scientific basis for evaluating the long-term performance of coatings, helping to select coatings suitable for use in the external environment and improving the lifespan and mass Stability of wood products.