Here is a Sunshine Beer Glass Sign from the Sunshine Brewing Company located in Reading, PA. This sign is considered an ROG (Reverse Over Glass) also known as a Reverse Painted Glass sign because the graphics are printed in the reverse on the back of the glass than sealed with a cardboard backer. Signs like these are very hard to find in any condition these days because they just never lasted in a bar or tavern scene and almost always were broken.
There’s actually a second variation to this sign with similar graphics; that variation reads “On Draught” instead of “We Recommend” as printed on this sign.