The test consists in measuring absorption when a single side of paper and paperboard is in contact with water for a certain time. The tester measures the size degree of paper and board paper to determine their resistance to absorption. The specimen is placed on a metallic plate on the rubber mat. On the top of the specimen of a certain area, a metallic ring is placed and fixed. Pour water up to the level of 10mm in the ring so that the water is gradually absorbed by the specimen. The difference in weight before and after wetting (absorption amount) is read to 0.01g as absorption degree.