In 1821 in a letter to his friend and patron the Reverend John Fisher, Constable wrote 'I associate my "careless boyhood" to all that lies on the banks of the Stour. They made me a painter (& I am gratefull)'. In the light of this it may be more than a coincidence that the focus of the composition of 'Flatford Mill' is a boy on a barge horse. Certainly, the strange signature in the foreground, painted as if scored into the earth by the artist, emphasises Constable's close identification with this particular scene of his 'boyhood', the stretch of the river from the footbridge, part of whose woodwork can be seen in the left corner of the picture, to his father's mill.
There is no doubt that this painting has an extraordinarily convincing naturalness. One of the ways in which Constable achieved this was by careful use of a wide range of greens to reflect the range he found in nature. The extent to which he did this was noted as innovatory at the time by the great French Romantic painter Eugene Delacroix, who visited Constable in 1825 and afterwards recorded in his journal, 'Constable says that the superiority of the green in his meadows comes from it being composed of a multitude of different greens. The lack of intensity and life in the foliage of most landscape painters arises because they usually paint them in a uniform tone.' The 'intensity and life' of Constable's paintings comes also from his way of putting on the paint in separate dabs. This gives the whole surface its own life and texture, directly expressing the life and texture of the scene, and Constable enhanced this effect with the flecks and dabs of pure white which can be seen for example on the clump of trees on the left in the middle distance.
Simon Wilson, Tate Gallery: An Illustrated Companion, Tate Gallery, London, revised edition 1991, p.48