The use of casting can also be found in the work of Rachel Whiteread. Much of Whiteread’s work is concerned with exposing invisible spaces by casting them. The physical use of the hot water bottle has also been subverted in that it is normally the receptacle of a hot liquid, whereas, plaster cools as it solidifies.

The artist David Connearn not only produces work under his own name, but also makes work which is exhibited under the name of sculptor Sol LeWitt. That is to say that Connearn is licensed to make sculptures by Sol LeWitt. Although made by the same person, the work of both artists is very different. Connearn makes drawings which look superficially very mechanical, but are nevertheless purely expressive. Using pen nibs of a pre-determined width, Connearn hand draws horizontal lines of an established width from one side of the paper to the other, a feat of intense concentration when lengths of two meters are involved. The drawings are both multiples and unique. It is possible to repeat the conditions of the drawing, but only Connearn can repeat the drawing.

Sol LeWitt’s ‘Open Pyramid’ was made by David Connearn, but unlike Connearn’s work, it is purely mathematical. If the conditions and the materials of the sculpture can be repeated, the sculpture can be repeated. The ambiguity is one of copyright. Much of Sol LeWitt’s sculpture concerns itself with mathematical progressions and sequences. To this extent, like mathematics, his work exists a priori, like the geometric forms in which it is realised. Thus the individual artist, and his personal expression, obfuscate and impede rather than aid the working process. Sol LeWitt’s sculptures are his own because his name is his own, otherwise they are multiples even before they are made.

Ideas of mathematical progression, draughtsmanship and individual artistic expression are brought to a logical conclusion in the drawings of Tim Head. In the drawing ‘Idiot Wind’ the artist has used a laser printer to repeat a scanned image. Here marks are converted into combinations of hexadecimal values which are stored in the operating system of a computer and then processed by graphics software which operates a laser-jet printer which then reproduces copies of the drawing as designated by the computer operator.

This line of enquiry is further extended into the third dimension by artists Michael Joaquin Grey and Randolf Huff who have taken computer learning programmes based on neural networks and genetic algorithms. Using these self organising systems, which are capable of simple behaviours when used in conjunction with a supercomputer, the programmes the artists have used create forms which behave like simple organisms. The forms resemble biological archetypes with life cycles, reproduction and locomotion codes and lexicons. The artists simply observe the resultant forms. Like Sol LeWitt’s forms they are archetypal and almost a priori but they differ in that they are organic rather than geometric. The information is then converted into high resolution three-dimensional laser-moulded versions.

As shown by Grey and Hugg’s work, another significant contribution to the making of contemporary multiple sculptures has been the development of new technologies. Julian Opie’s ‘Screen Saver, Imagine you are Driving at Night’, like Grey and Huff’s ‘Gametes’, is a sculptural work generated in Cyberspace. It can be moved into the space of any other computer monitor. This virtual landscape is also an archetype, not one specific road but an aggregate of all roads, a standardised journey which could exist as a 9cm floppy disk, itself a standard format.

Extending the notion of the recorded experience is Georgina Starr’s ‘Crying’, a u-matic video recording of the artist standing in the corner of her studio crying. Much of Georgina Starr’s work is concerned with the psychological response of the viewer to statistically repeatable circumstances.