A lithophane (French: lithophanie) is an etched or molded artwork in very thin translucent porcelain that can only be seen clearly when back lit with a light source. It is a design or scene in intaglio that appears "en grisaille" (in gray) tones. The word "lithophane" derives from Greek "litho", which is from "lithos" which means stone or rock, and "phainein" meaning "to cause to appear" or "to cause to appear suddenly". From this is derived a meaning for lithophane of "light in stone" or to "appear in stone" as the three-dimensional image appears suddenly when lit with a back light source.