Paper corner boards are made from two paper components:
Surface paper — kraft liner
- Standard kraft: 140–160 g/m²
- High-strength kraft: 180–230 g/m²
The kraft liner forms the outer faces and provides tensile strength and abrasion resistance.
Core paper — paper tube board
- Standard tube board: 360–420 g/m²
- High-strength tube board: 420–550 g/m²
Multiple layers of tube board are stacked, wrapped on both faces with kraft liner and pressed into shape on the corner-board machine. The more layers and the heavier the grades, the higher the compression strength of the finished board.
