As a work of art, a poster on London’s public transport system can rarely earn more than a quick glance. Posters may be primarily functional, perhaps encouraging us to visit a new part of town, yet in the past century posters on the Underground have featured some outstanding original work and have hugely influenced British artists.

The Art of the Poster at London Transport Museum examines this long history, displaying 60 original artworks, starting with John Hassall’s 1908 No Need to Ask a Policeman. The painting was commissioned by Frank Pick, who had recently been appointed as head of marketing for the Underground, to publicise a new map. It was the start of Pick’s 32-year relationship with the arts.

Pick attracted Edward Bawden, Edward Wadsworth and Graham Sutherland, as well as advancing the careers of newly qualified artists. Bright colours and modern illustration techniques ensured that the posters stood out, “Frank Pick was very passionate about making links with artists,” says the show’s co-curator Claire Dobbin. “By the 1930s London Transport had a reputation as a patron of the arts and wanted to continue that. They grew links with the art schools and that was where they would find a lot of the artists.”

With the posters shorn of their white borders and most of their text you can see what wonderfully intricate works these are and how ahead of their time many of the artists were. There are the modern illustrative styles of Abram Games and Tom Eckersley, as well as James Fitton’s 1948 mix of socialism and the space age. Looking at dates on the work can be surprising: Nancy Smith’s 1916 poster for Pinner is an obvious influence on one of the more recent poster artists, Paul Catherall, whose 2006 print of St Paul’s features on the jacket of the book that accompanies the show.

Catherall says: “A lot of my heroes and direct influences are pretty much from the artists London Transport used. It used to be that a postage stamp or a poster for London Transport was the thing to aspire to and that said you had arrived. I used to daydream about it when I was on the Tube. For me, it was a dream come true.”

But the exhibition shows that dream could become something of a nightmare for even the most accomplished of artists if they don’t quite fit in with the strict brief of informing first and impressing the critics second. Eric Ravilious’s beautiful watercolour of Greenwich Observatory was deemed “useless” when it came to attracting visitors to the area and was never used on a poster.

A similar fate befell a painting entitled Chilterns by John Nash. The show features Nash’s frantic letters to London Transport, which speak of the difficulty of portraying the idea of summer when painting in winter, as well as trying to capture landscape in portrait format. But his two years of toing and froing by mail were in vain and the painting sits as one of four such outcasts in this outstanding show.

The Art of the Poster – A Century of Design, London Transport Museum, London WC2 (www.ltmuseum.co.uk), to March 31; London Transport Posters is published by Lund Humphries (£30)

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