Instructions
To determine whether your shot glass is newer or an antique, look for differences in color. The more modern shot glass of the same design as an antique shot glass may reveal a difference use in color. Older glasses tend to use multicolor designs whereas newer models may use only a single color because single color glasses are cheaper to produce.
Feel for differences in weight. Older shot glasses tend to be heavier on the bottom than newer designs and the weight is mostly concentrated in the base where the glass is thickest. New shot glasses have a more consistent weight throughout the glass and the bottom of the glass is usually the same thickness as the sides.
Find the maker's mark on the bottom of the shot glass to identify glasses produced by companies known to produce glass during different time periods. The maker's mark typically has a distinct shape that identifies the company. Some companies also incorporate their initials into the maker's mark and combine them with a shape.