After outgrowing its cramped Greenpoint store, this rare-books and midcentury-modern-furniture shop upgraded to a large warehouse space, which was a repair garage in the 1920s. The primary-colored, Mondrian-looking exterior alerts passersby to the store’s covert entrance. Open Air Modern narrows its focus on collectible furniture and books strictly from the ’50s through the ’80s. Coffee tables, sofas and credenzas litter the periwinkle-walled space, lit up by for-sale fixtures such as an Achille Castigliano arc light ($600) and a slick postmodern Robert Sonneman desk lamp ($395). Post-WWII–designed furnishings are culled from auctions along the East Coast or imported from Europe. Preservationists will love the Danish teak, walnut, birch and rosewood goods, including a pagoda-style walnut desk ($795), Danish modern side tables (two for $425) and a set of Herman Miller pea-soup-green chairs (four for $500), but even owner Matt Singer admits that there’s an occasional piece of junky furniture. To keep you from purchasing the wrong stuff, about 2,000 books on design and art are stacked on architectural-framed shelves. Page through Finnish Modern Design by Marianne Aav ($68), Interiors for Today from the Whitney Library of Design and Studio Vista London ($28), and Cartier-Bresson’s France by Francois Nourissier ($95). There are also random finds, like High Fashion Crimes by Melanie Pullen ($75) and The Official Guide to the New York World’s Fair by Time-Life Books ($18), featuring exhibits from the 1964–65 extravaganza.