Photochromic Ink & Pigments – UV Light Sensitive
Colorless to Color when exposed to UV light
Three color kit - pigments react to UV rays from sun & black light.
Water-Based Inks change color when exposed to sun or black light UV.
UV Light Activated Thermometer Stickers, 30 Paper Label Stickers Per Sheet - Sticker size: 1" x 2-5/8"