I have have used this stuff for overcoating the paint job.........I have never had a problem with bad effects on decals, but those were mostly the decals that were in the box, which are kinda thick and indestructable. I don't have many (any?) after market decal sheets of high quality. The bottle on the left is Pactra AB 28 flat clear, and is about 100 years old. I have never used it much for some reason. I always wait about a week to apply this stuff.