1 of 10
Prisoners' art is on display at the 2004 Koestler Exhibition - a collection of award-winners from UK prisons, young offender institutions, secure units and high security psychiatric hospitals.

2 of 10
The pieces are picked from among 4,000 entries in 62 wide-ranging categories. They include painting, sculpture, pottery, furniture, speech, video, poetry and prose.

3 of 10
The Koestler Award Trust works through a whole range of creative arts to try to encourage prisoners' self-esteem and self-respect.

4 of 10
It was set up by Arthur Koestler (1905-1983), a former war and immigration detainee. He campaigned to give inmates creative opportunities to combat what he felt were prison life's dehumanising effects.

5 of 10
The Trust aims to address many prisoners' literacy and numeracy problems so they can go on to further education, training and, eventually, employment on their release.

6 of 10
Holiday destinations, ships, planes and travel often feature. Portraiture is also popular.

7 of 10
Some pieces are intricate calligraphy work, others are painstaking matchstick constructions. The hours of the sentence spent on their construction are recorded alongside.

8 of 10
The prison environment, freedom and absent loved ones are common themes. The prison, not the prisoner, is named in the exhibition.

9 of 10
"You can tell people have just done what's in their heart. What strikes me is the commonality - we are each in our own prison. I feel moved by it," says visitor Kathryn Carr, from Darlington.

10 of 10
The Koestler Exhibition 2004 is on at St Mary Abbots Hall, Vicarage Gate, Kensington Church Street, London W8, 10am-7pm, until Thursday October 7. Admission is free.