All those gold framed pictures you see hanging in museums? They're covered in gilt — a very thin layer of gold leaf, like paper, applied to the surface.
A common term associated with gilt is gilt-edged, implying something known to be reliably wealthy. Anything can be gilt-edged: a person, a town, or a reputation. The term comes from a form of government-issued bond, known as a gilt, which was originally gilded around the edges. Don't confuse gilt with guilt, which sounds the same but means a sense of knowing you've done something wrong. (Though, if you've stolen a gilt, does that make you gilty?)