The Lithophane was originally developed in Europe during the early part of the 19th century. Made of porcelain, they don't initially appear very impressive, just a collection of bumps and lines forming a picture. But a Lithophane is very thin, and when you hold it up to the light, a picture appears as if by magic!
It works simply because of the different thicknesses within the porcelain, and when light is shone through, the porcelain appears darker where it is thicker, and lighter where it is thinner.
Lithophanes were made by skilled artists who initially worked with a block of wax, and carved out a picture containing varying depths. The wax was then used to create a mould, from which the porcelain Lithophane was made.
We included a plastic Lithophane in the Grand Illusions Christmas pack a few years ago, and we have even come across a company that makes Lithophanes from chocolate.
Some Lithophanes were incorporated into drinking vessels, others into lamp shades. Lithophanes became less popular by 1900, and by the 1930s were hardly made at all. However recently there have been a few companies that have started making them again.