Observations: Artefects from classic stage sets show the value of theatre design

There's an Inca mask from Peter Shaffer's The Royal Hunt of the Sun; the bench that Laurence Olivier once sat on in Uncle Vanya; and a delicate Patrick Procktor watercolour of a theatre on green lawns shadowed by a golden oak.

Here are some glorious moments and artefacts collected by designer Pamela Howard in celebration of the Festival Theatre's 50th anniversary. The venue was not only the launch pad for Olivier's National Theatre in 1962, but is also, today, a creative lifeline for the West End.

The artistic process involved in stage design is little noted and too little preserved. Howard was anxious to have something from John Arden's great anti-colonial epic Serjeant Musgrave's Dance, an early production of the National at Chichester, but could find nothing at all. In desperation, she rang Albert Finney, who played the lead, and asked him if he had anything under his bed. He said he did have but had got rid of it.

She had more luck with Uncle Vanya; as well as the bench, she found a felt-pen drawing of the set by the great designer Sean Kenny – who designed Lionel Bart's Oliver! – in the possession of the actor Alec McCowen. There is Ralph Koltai's artist's model for an astonishing all-white 1968 production of The Tempest.

This exhibition shows that good theatre design is worth looking at – and not just in theatres.

'The Art of Chichester Festival Theatre: A Celebration' at the Pallant House Gallery, Chichester, until 10 June (www.pallant.org.uk)