Ever since 2009, Susan Barnett (b. 1951) has been roaming the streets of the world looking for T-shirts with eye-catching prints. On sunny days she stations herself in a busy place, camera in hand, ready to snap passers-by who advertise their views through their dress. Strong political statements or witty messages are her favourite targets. She observes, inventories and shows that the T-shirt – that quintessential piece of leisure attire – can be a significant means of expressing identity, exploring social issues or reflecting current political and cultural concerns.

Young or old, male or female, rich or poor, the subjects of her portraits stand up fearlessly for their political opinions, ideals or personal mantras. Since Barnett invariably photographs them from the rear, their faces remain unseen. For that reason, her Not In Your Face series answers the question of whether dress, body type and demeanour can tell us as much about a person as their facial features or expression.

Barnett’s fascination began in her home city of New York around seven years ago, when she saw a young woman standing at a pedestrian crossing who was wearing a t-shirt that had a African mask printed on it. She took a photo and was amazed at how much the image said about the woman, even though her face was concealed. Since then she has travelled the world, from New York to Berlin, from London to Copenhagen, and indeed to The Hague. Los Angeles’ Venice Beach Boardwalk is one of her favourite hotspots. Popular expressions, trending topics and slogans born there find their way onto backs everywhere else on the planet.

According to the American photographer and former gallery-holder, there has been a surprising change in the general tone of the messages since she embarked on her project. Just after the election of President Barack Obama, the slogans tended to be optimistic; now they are often angry and abusive.

The book T: A Typology of T-Shirts is an anthology of the photographs taken by Susan Barnett between 2009 and 2016. A selection of around fifty of them will be on show until 5 March in the lounge of Restaurant Gember (in the same building as the Hague Museum of Photography and GEM museum of contemporary art). The two museums are closing for building work from mid-September to the end of December. The T-Shirt Types exhibition can be seen throughout that period free of charge.

Susan Barnett’s book T: A Typology of T-Shirts is currently on sale in the bookshop of the Hague Museum of Photography (price € 39.50).