Jackson Pollack perhaps or Mark Rothko or maybe Cy Twombly? Would you believe it is a big sheet of paper the art teacher spreads out so the kids' paint won't spill on the tables? She uses it multiple times, and the paint continues to build up. Personally, I think it's pretty great.
Love it. Good question. Put a frame on it and it's art! Perhaps because the effects of a painter can also be created randomly, doesn't mean that which is similar but deliberately created isn't art. Maybe someone should pull together all those random acts of art and auction them for a cause.
