At nearly 78, American artist Ed Ruscha has promised to donate to London’s Tate museum one impression of all future prints he makes for the rest of his life. The initiative launched with the inaugural group of prints that includes “Jet Baby,” 2011, “Wall Rocket,” 2013, and “Sponge Puddle,” 2015, along with 15 other works reflecting the artist’s interest in signs, language, and the landscape of Los Angeles.