When a friend introduced author Sarah Thornton to art-world mischief maker Maurizio Cattelan as an ethnographer, “he seemed to mishear,” Thornton writes, “and exclaimed with great enthusiasm, 'You’re a pornographer!’” Not every player in Thornton’s new book “33 Artists in 3 Acts” makes the unforgettable impression that Cattelan does at every turn. Thornton, 49, who writes about art in a wide cultural frame, is the former chief writer on contemporary art at the Economist, where her career as an author bloomed. Born in Canada, she earned an undergraduate degree in art history at Concordia University in Montreal before a fellowship took her to the United Kingdom, where she earned a doctorate in sociology at the Strathclyde University in Glasgow. “My work is in between the entertainment industry, big market powers, the spectacularization of politics and everyday life,” said Mexican artist Gabriel Orozco. Thornton approached each of her subjects — including such reputedly or genuinely hard-to-handle characters as Jeff Koons, Cindy Sherman, Ai Weiwei and Damien Hirst — evenhandedly and with a sharp eye for their mannerisms and the potentially revealing paraphernalia of their working lives. The sociologist of music Simon Frith, Thornton’s mentor and doctoral thesis adviser at Strathclyde, repeatedly told her that “an ethnographer must have a novelist’s eye for detail,” said Thornton in conversation during a visit to The Chronicle. Of a visit to feminist performance and video artist Martha Rosler, Thornton writes: Rosler’s living room looks like a charity shop hit by a bomb. With my back to a Victorian bay window lined with plants, I look out onto a 55-foot stretch of strewn boxes, clunky old television sets, VCRs, paintings acquired at thrift shops, and women’s crafts such as lace doilies, beadwork pieces, handmade dolls, and pottery. Before the reader dismisses Rosler as a hoarder, Thornton writes, “Most of the stuff is destined for her 'Meta-Monumental Garage Sale,’ which will take place in the atrium of New York’s Museum of Modern Art.” Two questions press on the reader’s mind repeatedly throughout Thornton’s account of repeated encounters with artists, in their studios and beyond: “Another word for what ethnographers do is 'participant observation,’ which is kind of a joke to a lot of people,” she said with a liquid laugh. After “33 Artists …” and her previous, much-admired book “Seven Days in the Art World,” “I’m no longer an outsider to the art world, and technically an ethnographer should be an outsider,” Thornton said, but I feel that these artists with high levels of recognition, who end up customizing the role so much for themselves — you go into their studios and it can feel a little bit like a different planet. [...] “33 Artists in 3 Acts” entailed four years of interviews and research and many thousands of miles of air travel hopscotching four continents. Especially on these foreign trips, I’d interview several artists at a time, then you really have to make sure you’re fastidious because once you’ve gotten over your jet lag and returned home, without a system, who knows what you saw? To make the project manageable and the book readable, she ordered her accounts under three categories — the three “acts”: politics, kinship and craft, all subjects that get spun in unexpected ways by her interview subjects. For all its level-eyed address to its subject, “33 Artists …” will make some readers wonder whether it has a covert hero.