Banksy conservation begins
July 26 2011

Conservation work is progressing on an 'early Banksy' in Bristol, after the owner of the building on which it is painted whitewhased it out. Saheed Ahmed had painted over the graffiti because he 'thought it was worthless', and didn't like the mess. But now, after being told it could be 'worth £100,000', he is paying to have the whitewash removed (as you can see above).
Here is what the wall looked like with the Banksy.
And here is what it looked like as Whitewash on Stucco Wall, with Bins, 2011, by Saheed Ahmed. Which do you prefer?
I sometimes see Banksys in conservation studios, particularly works on canvas. They don't have a very long shelflife. The spray paint effectively eats the canvas.