Outsiders are broadly defined as self-taught artists who paint from an inner compulsion, rather than from the pursuit of fame and fortune. They often come from the fringes of society.
The new fashion for Outsider art was underlined last year when the Los Angles County Museum mounted an international travelling exhibition. The second annual Outsider Art Fair took place in New York 10 days ago.
Louden, 50, whose work is on show at the Boundary Gallery (98 Boundary Road, London NW8), is an ex-lorry driver. He depicts a brilliantly coloured world which defies perspective, mostly using crayons on plyboard. Small figures are often contained in large ones; a screaming woman may be as tall as a skyscraper. 'Sometimes it surprises me what comes out,' he said.
He painted in his spare time for 20 years before he was 'discovered' in 1981 by Victor Musgrave, the founder of the Outsider Art Archive in London.
Musgrave bought a group of paintings from Louden, at some pounds 4 a time, and went on to organise a one-man show at the Serpentine Gallery in 1985 which was a sell- out, with prices hitting pounds 200.
Louden was exhibited internationally under the wing of the Outsider Art Archive but was thrown out in 1991 by Musgrave's partner, Monika Kinley (who inherited the organisation at the founder's death) because of his first show at the Boundary Gallery.
Ms Kinley holds that contact with commercial galleries destroys the originality of an Outsider's vision. Louden, on the other hand, feels he deserves to make more money out of his paintings; prices in his current show range from pounds 700 to pounds 4,500.
Michael Quanne, 52, has been in and out of prison all his life. He is showing at the Bruton Street Gallery (28 Bruton Street London W1), also had his first major show in 1985, at the Camden Arts Centre in north London, and it was also a sell-out - although he had won the annual Koestler painting award for prisoners 10 years before. His great backer is John Berger, art critic and Booker prize winner, who has written an introduction to the show.
Quanne's painting does not fall within the Outsider Art Archive's remit, which requires a visionary element. Quanne's pictures, mostly street scenes in the East End of London, would normally be described as 'primitive' or 'naive'. However, they contain a bleak comment on the human condition; his children are always miniature adults, with all their vices and deviousness, while his adults are herded like children. He paints in oil on canvas and the pictures at the Bruton Street Gallery range in price from pounds 1,500 to pounds 6,500.