We do our tailgate lettering two ways; if the letter paint is to match some paint on the body we first paint the whole gate the matching color, use stick on letters that have been rubbed on a fuzzy cloth to kill some of the adhesion which are then stuck in place and then the body color is sprayed. When decals are removed the desired color is on the letters ( Chevy pickup). If stick on letters are used a light coat of clear is dry sprayed (prevents curling) over the decal letters followed by several heavy coats of wet clear. This "Decoupages" the letters into place forever. (GMC pickup).