Reverse glass painting is a painting technique in which the image is painted in reverse on the back side of a piece of glass. This technique became popular in 13th century Italy and is still used today.
Some other names for this process are "verre eglomise" in French and "hinterglasmalerei" in German.
Reverse glass painting was very popular in the 18th and 19th centuries. Many antique examples are from this time period. Reproductions of 18th century Chinese paintings are also common. Antique clock faces are another popular application of this process.
Reverse glass painting kits were sold to hobbyists starting in the mid 19th century.