Dogs Can’t Read. Duh! Vertical Wall Decals is a simple alternative to painting on walls. Wall decals (or clings) are re-usable and repositionable self-adhesive stickers that don't leave any residues. Wall decals are made from a woven polyester fabric with a clear, acrylic and ultra-removable adhesive. Printed with custom-developed, archival, acid free pigment inks.