Ryosuke Cohen is well known in the mail art circles. His mail art project Brain Cell runs since 1985. ‘The project is a networked art project where individual artists contribute stamps, stickers, drawings or other images. These are sent through the mail to Cohen, who assembles and prints them as part of each cell. He prints 150 copies (30 x 42 cm) with a small silkscreen system called a Cyclostyle (now out of production). Each participant is mailed a Brain Cell print along with a documentation list of contributors worldwide.’ (wikipedia). Brain Cell has enlisted over 6,000 contributors from 80 nations since 1985. Every sheet of Brain Cell is numbered. This one is No.942 and has stamps and stickers from 49 mail artists.