Abstract: A polylaminated, waterproof, thermally-sensitive decal has a waterproof base that is adhesive on its outer surface and printable on its inner surface; an advertising image printed on the inner surface; a printable covering that overlays the advertising image; a layer of thermochromic ink on the printable covering such that the thermochromic ink is opaque at room temperature but is translucent at increased temperature; and a waterproof layer designed to overlay and protect the thermochromic ink in a moist or wet environment. The decals are designed to fit within the confines of a urinal and to act as a target for the user. The decals are easily applied and removed and are intended for use in moist or wet environments. Also disclosed is a method of advertising.