Best in show | Upnor Castle, Kent, 1831-32, by JMW Turner

“A beautiful sun in a dappled sky and its sublime reflections on the water are classic Turner at a point in his career when you start to see outside influences on his work.

In the 1820s and 1830s, for example, a wider range of yellow pigments emerged, and Turner made full use of them in his experiments with the effects of light and shade, particularly in his skies, which he often infused with golden luminosity.

There’s also a strong link between this picture and the work of Claude Lorrain, which Turner described as being unique in its use of ‘the amber-coloured ether’; he was full of admiration for the French artist’s ability to capture every colour and hue of the summer.

You feel the summer heat in this picture, particularly in the way the sun’s rays extend upwards while also being mirrored on the still water.

People often think of Turner purely in terms of the picturesque, but he was always interested in depicting the realities of rural and coastal communities.

There’s a lot of ordinary maritime life in the foreground with fishermen hauling their nets in after a long day while others rest on the shoreline, all in the shadow of the grand castle on the bank of the River Medway.

This exhibition offers visitors a rare opportunity to see the collection of watercolours for which the Whitworth is renowned. It has been decades since we’ve put so many on display because of their particular environmental needs.

It also features the first showing in many years of the complete set of Turner’s Liber Studiorum – ‘Book of Studies’ – series of prints.

Turner was just as good at printmaking as painting and approached the print medium with the same expressive freedom seen in his oils and watercolours, fully exploiting the tonal possibilities of etching and mezzotint.

The Liber was an ambitious project and the print medium – to which he turned when he was already an established Royal Academician – was to have a long-lasting and significant influence on him.

When he died, Turner left behind canvases still influenced by Liber subjects, long after his move into more impressionistic oil painting. He famously claimed it was a print by Willem van de Velde the Younger that made him want to be an artist.

The show aims to highlight the reciprocal relationship across all his media. We want visitors to look at the prints, oils and watercolours such as this one as parts of a broader creative output. We are delighted to celebrate the 250th anniversary of Turner’s birth this year by displaying the Liber and watercolours, alongside significant loans, in just the way Turner liked his work to be presented.”

Interview by John Holt. Turner: In Light and Shade runs at the Whitworth until 2 November