The late 19th and early 20th century in France resulted in some really beautiful work, especially on the boulangeries and patisseries (bakeries and cake shops) in and around Paris.
During the time, the merchants were doing well and wanted more impressive shopfronts. Displaying bread in a window isn't much good for the produce, so they had windows painted with pictures and gilded decorations and lettering.
There are a good number of surviving examples. Pictures are typically painted on canvas and then glued onto the back of the glass. They are often rural scenes of sowing and harvesting. There's also paintings of sheaves of wheat, and various related imagery.
I note with considerable interest the transom signs which are glass with letters. Sometimes they are gilded or painted. On some they appear to be manufactured letters that are glued onto the back of the glass. I'm fascinated by the techniques used as it's hard to tell exactly how they're done from pictures , but also the sheer size of the glass, given the ae of these pieces. I'd love to see one first hand.
Several studios were doing this work, the best known being Benoist et Fils, which ran for three generations, eventually finishing in the 1930's after the grand era was long over and people were looking for a different design aesthetic.
I bought a book recently; Boulangerie by Paul Rambali with some great photos of the shopfronts.
There's also a very good website at http://www.ruavista.com/
http://www.ruavista.com/bakeries.htm
Denver Chapter of the Letterheads