Share And Keep Apart
Many on one surface, each recoverable.
Formerly Multiplex
One sheet, three keyed hands.
Seen in Janet Cardiff, The Forty Part Motet, 2001
Try it on your work
Three people, one surface. Each chooses a kind of mark nobody else may use: a colour, a tool, a line weight. All work at once for five minutes without coordinating. Stop. Each must be able to trace only their own. If someone cannot, the key was not distinct enough; fix the key, not the drawing.
Write a text in which three threads run at once, each marked by its own tense, person or typeface. Stop when each thread can be read alone from start to finish by following its key, and the whole can be read as one.
Run three projects through one week by giving each a fixed key: a day, a desk, a notebook. Never mix keys. Stop at the week's end. If each project's record can be recovered cleanly, the channel was shared without loss.
How it has been used
Wavelength-division multiplexing sends several data streams through a single optical fibre by assigning each stream a different wavelength of light. At the receiving end, the wavelengths are separated and the streams recovered. Sharing the channel does not require merging the messages or giving one stream the whole fibre.
Where it leads
Grouped under Put different things into contact