The TAPPI T 431 standard specifies a test method for the ink absorption performance of blotting paper, which is mainly used to determine the rate at which blotting paper absorbs writing ink. The test is carried out at 23 ° C and its blotting mass is assessed by measuring the time it takes for blotting paper to fully absorb 1 mL of ink. The results of this method can be used to predict and specify the absorption performance of blotting paper, which is widely used in quality control and product development to help optimize the performance of blotting paper and ensure its suitability in writing, office and other scenarios.