Ars longa, vita brevis. Not all art is designed for the ages. Sometimes the artist wants to create something time limited. For example, Andy Galsworthy creates environmental art designed to disappear into the landscape, perhaps washed away by the next tide or rotting away on the forest floor. A tagger knows that there's a fair chance his piece will be painted over before very long.
This piece in Southampton tacitly invites the viewing public to contribute to its degradation. The discolouration after only a few months shows that there has been a good take up by the public. It is good to see folk getting involved in art in their community.
Well done people of Southampton.