Lessons in graffiti do not normally appear on a school timetable.

But youngsters at a Sussex school have been learning how to appreciate tags as art.

The idea of the project at Thomas Bennett School in Crawley is to stop future criminal offences by changing pupils' perception of graffiti.

It was the brainchild of Mike Lemmon of the community safety unit at West Sussex County Council and youth worker Amanda Smith.

Mr Lemmon said: "The difference between graffiti as an art form and graffiti as vandalism is one word - permission."

"Graffiti can be an art form and this scheme is about exploring what young people can do with their talents. It's about being creative and thought-provoking."

Rarekind is a group of young people based in the North Laine in Brighton who have made a business from graffiti.

They have their own fashion range, music and web site and support education departments who want to engage young people in art.

Tan and Will from Rarekind agreed to visit a group of Years 7, 8 and 9 pupils to show them the artistic skills behind their work.

They have just finished a commission at Harvey Nichols in Knightsbridge and are flying out to Barcelona for another commission at the Sonar music festival this month.

Will, 21, said: "The problem with street graffiti is that there isn't enough good stuff so it can look a mess but also the local councils are quite uptight about allocating space for graffiti artists to use."

Pupil Stephen Burton, 14, said: "I used to go out tagging a bit but I've learnt a lot from this. There should be more places for people to be allowed to do it."

Art teacher Fiona Fletcher said: "It's been fantastic to see the students engaging so much with this and it's great to see them learning the same things about hot and cold colours from Tan and Will as we teach them in class."

The finished canvases will be displayed in the new Thomas Bennett building and there are plans for more at Broadfield Youth Centre.