Glass Alert window stickers are made out of long lasting, professional grade, self-adhesive vinyl - they are not window clings. The frosted design is the same on both sides and can be applied to inside or outside surface of the glass. Exterior application suggested for glass with heavy tint or mirror finish. Stickers are not repositionable, but since this is a high grade vinyl you can clean your glass with the sticker in place. The frosted vinyl designs are visible on glass, but also somewhat translucent so they do not obstruct the view outside of your window or sliding glass door. Glass door safety or warning stickers that alert you to the glass while still looking decorative, for use in home or business.