I discovered this trick after my local hobby shop closed. I was about to clear-coat some decals but had no flat clear. I did have some white glue and water, though, which I mixed in an experiment to see if it would work as a substitute. It dries dead flat (and very quickly), is water-soluble, and, best of all, it is cheap. It worked very well, and now I use it for small areas, over small decals, or where the paint has been rubbed shiny in places it should not be.

Tip submitted by:
Jon GraftonTulsa, Oklahoma