One of the perks of having a mother who was very into both garage sales and interior design was growing up in a house filled with wacky old design books from the 1960s and '70s. In their pages, I was exposed to many strange and wonderful things, not least among them supergraphics, the crazy stripes and arcs and rainbows that covered every surface of a room, irrespective of walls or floors or furniture. As part of a series about strange old design trends (perhaps unjustly) relegated to the dustbi