The conversation between human and AI assistant.
[|Human|] Given this paragraph about material, what is lithophane?
[|AI|] A lithophane is a thin plaque of translucent material, normally porcelain, which has been moulded to varying thickness, such that when lit from behind the different thicknesses show as different shades, forming an image.
[|Human|] 
Given this paragraph about material, what is lithophane?