The TAPPI TIP 0404-43 standard specifies a test method for the water permeability of pressed fabrics. This method is suitable for the measurement of the water permeability performance of fabrics in the press section of paper machines, enabling the detection of fabrics in operation without downtime. Through this method, it is possible to monitor the change of water permeability of fabrics during their service life, evaluate their differences in water permeability in transverse (CD) and longitudinal (MD), and identify localized areas of high or low water permeability. This standard provides the paper industry with a scientific means of evaluating fabric performance, which helps to optimize the pressing process, improve paper mass and production efficiency.