The American Paper Institute originally promoted four different variants of the recycling symbol for different purposes. The plain Möbius loop, either white with an outline or solid black, was to be used to indicate that a product was "recyclable". The other two variants had the Möbius loop inside a circle—either white on black or black on white—and were meant for products "made of recycled materials", with the white-on-black version to be used for 100% recycled fiber, and the black-on-white version for products containing both recycled and unrecycled fiber. For example, a paper envelope might have both the first and last of these four symbols, to indicate that it was recyclable, and made from both recycled and unrecycled fibers.