Did you ever look at a large expensive building covered in glass? That glass is usually coated with some exotic materials to reflect heat in either direction. Some glass manufacturers are even shipping self cleaning glass. If you look hard, some of those large glass panels have stripes on them. Builders and architects hate that; so do I.
The stripes are usually caused by variations in the thickness of the coating material causing light to reflect non-uniform angles. A glass coating company I recently visited was coating sample pieces and was struggling with that same problem. This glass company was vaporizing a super secret liquid precursor for coating glass. In this process the vapor traveled through a very hot slot (as wide as the glass) over hot moving glass where a surface reaction takes place causing it to bond with the glass.