GB/T 31905-2015 "Paper and board — Determination of edge wicking" specifies the methods for determining the edge wicking mass and edge wicking distance of paper and board, applicable to paper and board used in the production of packaging for liquids. The test specimens are sampled according to GB/T 450, conditioned in accordance with GB/T 10739, and a specific apparatus is used to bring the edge of the specimen into contact with a liquid. The mass and distance of wicking are recorded over a specified period. The standard references GB/T 451.3 and GB/T 461.1, among others. The results are reported as the average of three determinations, rounded to two decimal places, and are used to evaluate the resistance of paper and board to liquid penetration from the edge.