In the quest to provide the end user with high-performance corrugated containers which achieve better stacking strength, the mills have developed a range of liners that have superior ring crush levels. If properly combined, they will yield high-performance top-to-bottom compression characteristics. This property is particularly important as the end use demands of stronger boxes, at reduced fiber levels, that will survive taller than ever before stacking levels in modern high-density warehouses. Mills utilize a number of techniques to achieve higher compression strength, including improved fiber orientation and cross-linking, and high density formation of paper fibers through high loading rates of their presses. This densification process compresses the fibers together tighter, thus increasing the sheets density and strength.