One way to identify a vintage decanter is by the use of lead crystal, which was invented in 17th-century England and favored because of its high level of transparency. If the decanter is made of blown glass, some characteristics include long, round necks and flat bases for storage on cellar floors.
Vintage decanters that were used for strong spirits have small mouths that allowed users to pour the liquid into it with a funnel, while decanters for wine have wider mouths for direct pouring. Vintage decanters used for liqueurs, such as Chartreuse, are clear so people could identify the liquid in them. Some vintage decanters feature a ewer with a handle and gooseneck spout, while others feature flat bases that made it hard for them to tip over.