The performance of Corrugated Board in real-world environments is profoundly affected by humidity. Cellulose fibers in the board are moisture-absorbent, and increased environmental humidity significantly compromises the material's rigidity. This reduction in stiffness can drastically lower the board's Compression Strength, sometimes by up to 50%.

This loss of compression strength can lead to the catastrophic failure and collapse of stacked boxes in humid warehouses or cold storage units. To counteract this, designers must specify boards made with Virgin Fibers or those featuring specialized moisture barriers when designing packaging intended for high-humidity environments.