IN KUBRICK'S 2001
ON PLANET JUPITER.
Some of the more elaborate tiles also feature cryptic political statements or exhort readers to create and install similar tiles of their own. The material used for making the tiles was long a mystery, but evidence has emerged that they may be primarily made of layers of linoleum and asphalt crack-filling compound.
Articles about the tiles began appearing in the mid-1990s, though references may have started to appear in the mid-1980s.