GB/T 2679.8-2016 "Paper and board—Determination of compressive strength—Ring crush method" specifies the method for determining the ring crush strength of paper and board using a compression tester. It applies to paper and board with a thickness ranging from 0.10 mm to 0.58 mm and is a modified adoption of ISO 12192:2011. The test specimens are 152.0 ± 0.2 mm in length and 12.70 ± 0.1 mm in width, with 10 pieces taken in both the machine and cross directions. They are conditioned according to GB/T 10739. Compression is carried out at a speed of 12.5 ± 2.5 mm/min until collapse, and the maximum compressive force is recorded. The ring crush strength and ring crush strength index are calculated using the provided formulas, with results rounded to 0.01 kN/m and 0.1 N·m/g, respectively.