After the exhibitions, postcards will be sold in support of Hospital Rooms, Winsor & Newton's charity partner bringing artist-designed, therapeutic environments to mental health wards across the UK.

A curated selection of postcards will be exhibited in New York and London, in a physical celebration of the Art Mail artist community.

Every postcard received during the campaign will be automatically entered into a prize drawing to win one 100 sets of Winsor & Newton watercolour. Must be 18 or older to win. See terms and conditions below for details.