Plywood is made from layering sheet veneers with grain directions alternating by what degree?

• A. 0°
• B. 90°
• C. 45°
• D. 180°

Answer: (B)

Cross-graining is the idea here. Plywood is built by layering sheets of veneer with their grain directions turning 90 degrees from one layer to the next, so the grain alternates by 90 degrees. This cross-lamination makes the panel strong and stable in both directions and greatly reduces warping or twisting from moisture or changes in humidity. If the veneers all ran in the same direction (0° or 180°), the panel would behave more like a single-direction board and be more prone to expansion, contraction, and distortion. A 45° orientation changes the direction of stiffness and is used in some specialized products, but the standard plywood construction relies on 90-degree alternation.