Any graphics element like UI, sprites, meshes etc. that uses textures with transparency, can potentially suffer from white edges around transparent areas.
Hammered gold, or a “hammered” look in general can be a very charming and desireable look, as it gives a feel of something handmade and naturally worn. It is also applicable to give objects an antique look.
Though this article is based on RenderMan 21.5 for Maya, it should be easily modified for any application using RenderMan.