Artist floats a gut reaction to his critics: A Royal College of Art exhibition for sculpture students opens tomorrow. Dalya Alberge reports

DESCRIBE Tim Noble's sculpture as excrement and he will not take offence. Indeed, that is what his work is made of. 'Yes, it's mine', he said.

Yesterday, Mr Noble, 27, a postgraduate student at the Royal College of Art, was preparing his sculpture for the first-year students' show, which opens tomorrow. Into the top of one of two slim glass pedestals he had poured a mixture of excrement and water. A second container was filled with cream. 'At the moment, it's single cream. I'm going to use double cream. It will work better. It's thicker.' An electric fence cordoned off the sculpture.

His inspiration came from a friend's reaction to his acceptance by the RCA. 'He said, 'Tim, remember the shit and the cream always rise to the top'. I could have been either. Of course, it may be seen as a metaphor for art being a load of crap.'

Peter Blake, the pop artist and a former student of the RCA, said: 'This piece sounds like just another daft idea. For a long time, there have been so many daft ideas in art.'

Glynn Williams, the RCA's Professor of Sculpture, got his first glimpse of the exhibit yesterday. Turning to his student, he said calmly: 'Your work is usually about moving sculpture; this is about movement, not moving.'

Mr Noble is following in a tradition of artists using body fluids, though critics will feel that art has once again reached the bowels of degeneracy. In the Sixties, Piero Manzoni showed 90 cans, in a work called Merda d'Artista, each filled with 30 grams of his excrement. More recently, Helen Chadwick and Andres Serrano have both used urine in their photographic work.

Mr Noble, on a two-year course, is one of 36 sculpture postgraduates at the RCA. The annual cost of putting them through the course is about pounds 6,000 each. Professor Williams said that this work was untypical and it was a shame Mr Noble's revolving sculpture emblazoned with the word 'Hype' was not ready.

Sue Webster, an artist who was helping put the piece together, pointed out it was 'starting to smell'. Mr Noble said: 'It won't soon. It will be sealed - airtight.'