"Please Wash Your Hands" Decal By SmartSign | 3.5" x 5" DURABLE. Labels are made of 3 mil polyester with a brushed metal surface. The metallic polyester surface is tear, UV, water, salt-spray, oil and chemical resistant. INSTALLATION. Labels come with high-strength acrylic adhesive on the backside of the label to prevent tampering or peeling when applied to any flat surface. EASY TO CLEAN. Labels can be easily wiped off to clean contaminants such as dirt or dust. Labels can withstand most mild acids, alkalis, or salt solutions.