Gerhard Richter and Hans Ulrich Obrist first met in 1985. Their professional collaborations began seven years later, when the 24-year-old Obrist curated his first Richter exhibition; the following year he published a collection of his writings. Now Gerhard Richter has dedicated an artist's book to this longstanding relationship. The texts in "Obrist-O'Brist" have been produced by rearranging Obrist's interviews using a random generator, setting the results in blocks without discrete passages or paragraphs. The color plates are made up of photographs-both portraits and mementos-of Hans Ulrich Obrist, from the past 15 years, and photos of Richter's own paintings, which Richter has then painted over using brushes and scrapers. Chiming with many currents in contemporary writing and bookmaking, "Obrist-O'Brist" is an adventure from cover to cover; it even has two different sleeves, and can be approached from either end (as frequent upside-down pages indicate).