In this study, 5x5x12 single-wall RSC corrugated boxes were strengthened to increase their compression strength using four different methods; horizontal brace, diagonal brace, L-shape corner post, and triangular corner stiffener. All braces are of 2-inch width.

• Horizontal Brace: Compression strength increased by 9% when the unsupported box height was reduced from 12 inches to 3 inches.
• Diagonal Brace: Compression strength increased by 8% and 14% for single and double braces, respectively.
• L-Shape Corner Post: Compression strength increased by 29% and 38% for exterior and interior posts, respectively.
• Triangular Corner Stiffener: Compression strength increased by 36% when the stiffener depth increased from 0 inch to 9 inches.

The interior corner post method was the most effective and most practical.