This is a problem with the surface treatment of the acrylic plate before printing. For printed parts processed by printing after printing, special attention should be paid to the adhesion fastness of the ink, and the fastness is often related to the surface treatment. It is easily loosened by mechanical force during reprocessing. This print must be cleaned with special care before printing. It is best to clean with acetone, but it should be noted that the flash point of acetone is very low, and smoking is strictly prohibited when cleaning.