Английский Этимологический словарь - staple (2)

- "principal article grown or made," 14c., "official market," from O.Fr. estaple "market," from a Gmc. source akin to M.L.G. stapol, M.Du. stapel "market," from the same source as staple (1), the notion being of market stalls behind pillars of an arcade. The sense of "principle article grown or made in a place" is 1616, short for staple ware "wares and goods from a market."