Copyright Conundrum

We all now that inspiration can come from anywhere - but I didn't imagine it might come from some teenage graffiti on an old desk. This image to me is pure art - a random collection of marks made by many hands on a canvass which happens to be part of a school table. I call it 'accidental art'. I cannot attribute it to any one person and as the intention was not to create a piece of work I'm guessing the copyright police would be on the side of the photographer - should it ever sell for millions (offers considered). It's part of a series which may one day appear in an exhibition - I will credit the school I think, although I'm not sure if they would appreciate some of the other graffiti I managed to capture.