The Piazzetta c. 1911

John Singer Sargent made this watercolour painting of The Piazzetta, and what strikes me is how he’s built up the image through transparent washes, one layer over another. You can almost see the process as you look at it, like a map of his decisions. There’s a kind of lightness to the whole thing, partly because of the medium, but also the colour palette. It’s all pastel shades, pinks and blues, ochres and greens, and he’s applied them with a kind of freedom, letting the colours bleed into each other. Look how he’s suggested the crowds of people with just a few dabs of paint, or how the reflections in the water are just a series of horizontal strokes. It all feels so immediate and effortless, but you know that it took a lot of skill to achieve that effect. There's a similar playfulness in the work of Manet, though his paintings have a harder edge than this one. What I take from both of them is how much room they leave for interpretation. They don’t tell you what to think; they invite you to think along with them.