When exposed to sunlight or ultraviolet (UV) light, the molecular structure of the paint changes causing the photochromic compound to change color. This effect is reversed when the light source is removed or obstructed. Get creative and customize anything from Shoes, Wood, Paper/Cardboard, Canvases, Fabric, and so much more! For porous surfaces like fabrics, canvas, raw wood, paper, etc. you can use any traditional paintbrush or airbrush to apply the paint. For non-porous surfaces like leather, plastic, glass, etc. we strongly recommend using an airbrush to apply the paint. Painting on a non-white surface? We recommend using Langus Goods Flat White Base Coat on the surface before applying any color-changing paint.