MONTREAL — While the big glitzy art fairs in New York, London, and Miami often grab the headlines for the sheer volume of ostentatious art, celebrity-friendly promotions, and over-the-top displays, many people overlook the range of excellent small fairs that appeal to discerning collectors in different demographics. One such fair, now celebrating its sixth year, is Papier13 in Montreal, which opens today and features 42 galleries from across Canada. A compact fair devoted to works on paper (papier means "paper" in French) is a sophisticated and comfortable art-browsing experience dropped on an empty lot across from the city's contemporary art museum and other attractions.