Other variants ♾, an infinity sign (∞) inside a circle, represents the permanent paper symbol, used in packaging and publishing to signify the use of durable acid-free paper. In some ways, this logo expresses the opposite intention from the recycle logo, in that the acid-free paper is intended to last indefinitely, rather than being recycled. Nevertheless, acid-free paper does not usually contain toxic materials (although certain inks do), so it is easily recycled or composted. A satirical version of the classic recycling logo also exists, in which the three arrows are twisted from a circular pattern to pointing radially outward, thus symbolizing wasteful one-time usage rather than environmentally friendly recycling. This message is reinforced by the circular inscription, "THIS PROJECT WAS ENVIRONMENTALLY UNFRIENDLY", surrounding the modified logo. The satirical logo appears in the 1998 catalog of an installation art work in Bayonne, New Jersey, in which the artist Steven Pippin modified a row of glass-doored washing machines in a laundromat to operate as giant cameras. The cameras were used to take sequential photographs in the manner of pioneering stop motion photographer Eadweard Muybridge. The front-loading washing machines were then used to develop and process the 24 inch (61 cm) diameter circular film negatives. See also Green Dot symbol List of international common standards Japanese recycling symbols References Further reading Jones, Penny; Powell, Jerry. "Gary Anderson has been found!". Resource Recycling: North America's Recycling and Composting Journal, May 1999. Everson, Michael; Freytag, Asmus (2001-04-02). "Background information on Recycling Symbols" (PDF), ISO/IEC Working Group Document N2342 44 Recycle Logos and Symbols External links Certification marks Consumer symbols Recycling Symbols introduced in 1970