In my book, it’s not an art fair if you don’t spend time with a Picabia. (Helpfully, the Dadaist made quite a bit of work.) Here’s 1935’s Transparence (Deux têtes) at Hammer Galleries of New York. A special wall label notes that its cracked surface was intentional. The artist was, at the time, very into fashioning phony antique-looking craquelure.