Boards
Imagine this...
strolling through London's trendy Shoreditch, probably with a bit of Weapons of Mass Belief / righteous white rap in your headphones...
Seeing a blank piece of wall and having a brainwave
coming back to it later with a marker pen
and writing
"THIS IS A CANVAS"
THIIIIIINKABOUUUUUUT IIIIIT!
slow
fucking
clap