"In the quest to find the perfect canvas, some artists' imaginations, exceed their financial or physical means. Sometimes the canvas if bigger than ourselves - look at Banksy or Michelangelo, or Subway cars in the 1970s and 1980s. Sometimes the canvas is tiny. And free. And government-issued." "Label 228 is a gathering of street art executed on priority mail labels (Label 228, in USPS parlance) and displayed in public spaces. It's a remarkably popular method of exposure featured by graffiti.