Ed Ruscha is one of the great Pop artists, but he’s not a household name. That’s probably because his projects look completely unlike one another — from black and white photographs of the Sunset Strip to luscious drawings of words that he did in the 1960s. Words such as “Squirt” and “Pool” and “Dude,” floating in 3d illusion above swirling, cloudy backgrounds. They’re drawn in materials like gunpowder, lettuce juice, grass stains, Pepto-Bismol, and blood. Sarah Lilley explains.