ASTM D3450-15 (2020) standard test method is used to evaluate the washability of indoor architectural coatings. This method tests the ease of removing dirt from the coating drying film by using abrasive or non-abrasive cleaners. The test results help determine the tolerance of Coatings in the face of dust and dirt, affecting their Appearance retention during long-term use. This method is particularly suitable for measuring the cleaning effect of different Glossiness Coatings, and is not suitable for all types of dirt. Through this test, users can understand the cleaning convenience of Coatings, helping to make more appropriate decisions when choosing Coatings.