The origin of these pieces is taken from the even earlier art of the paper silhouette. An art form where a figure such as a human profile was portrayed by cutting out the silhouette with black paper and then pasting it to a white ground and framing under glass.
Most were in what many used to refer to as the story book style, Fairytale, or Wizard of Oz style. A style that was a highly popular one during the late 1910-30's period, but carried over until the late 1950's early 1960's.
The images were every conceivable fantasy and contrivance that one can imagine. Every thing from happy cowboys and Indians silhouettes to 18th century lovers. The lovers theme being one of the most common.
Many times they were sold as pairs having a carryover background and male female silhouettes playing off of each other.
I was fourtunate to pick up a good sized collection from a local collector a while back and have them currantly available at Antiques Plus. Above I have an image of some of them. Below I have a few close ups to illustrate some of the many different vingettes that are available. If one wishes to view them in person, just stop on by and have a look, but one might want to hurry. As of the time of this post I have already sold a couple of the ones that I have pictured here. These nostalgic pieces always go quickly.
These Silhouettes on Glass have become popular enough for a price guid to have been published in 2000.
Vintage Silhouettes on Glass & Reverse Paintings by: Shirley Mace
and it is available on the internet