While some museums are still somewhat skittish about selling souvenirs, New York's celebrated MoMA leads the way in retail innovation, its design boutiques almost as popular as the artwork on display.

The museum opened its first shop in 1939 - a simple sales counter on the MoMA premises on 53rd Street in Manhattan.

More than 70 years later, it has five retail spaces in New York, two of them devoted to design, a store in Tokyo and online shopping sites, two of which cater to the Japanese and Korean markets.