Hundreds of knitters around the world have begun wrapping their huge woolly creations around public property like trees, street signs and lampposts.
They then take photos of their colourful “art” and post them on internet sites for fellow knitters to view and comment on.
One of the most ambitious pieces of work saw a woman spend an entire week covering a disused single decker bus in colourful swatches.
The phenomenon, called Yarnbombing, is thought to have originated in the US but knitters are now beginning to cover British streets in woollen ‘tags’.
Quite often dozens of balls of coloured wool are used to make huge sleeves or cosies which are then stitched onto a fixed object, sometimes done under the cover of darkness.
Artist Sarah Hardacre, 31, from Salford, Manchester, has taken up Yarnbombing in her spare time.
She said: “Yarnbombing is all about using the street for making art.