This is what is known as a shaded etched piece of art work. It is created by drawing, cutting, and sandblasting different elements of the design at different times or stages. Shading give a dimensional depth effect while just dusting the glass.This art work can be used to hang in a window with a dark background such as trees, fences, parking lots, or even on a wall. Those dark elements help to show off the monochromatic scale of what shaded etching provides. Its a lovely art form.