The store specializes in Polish prints, ceramics, textiles, glassware, religious iconography and jewelry as well as one-of-a-kind Polish art, with Ms. Merska’s own pajaki hanging from the ceiling.

Even in the 30-odd volumes of Oskar Kolberg ’s extensive study of Polish folk culture, he makes little mention of this matter. The explanation for this is actually quite prosaic. Kolberg set out on ...