By the 1980s Heron was utilising wildly expressive and pure, abstracted form in his practice. May 11 1986 I is a bold and daring exploration into colour and space, where vibrant and contrasting oranges, purples, reds, yellows and blues combine and endlessly vibrate against one another.

Discussing his move into abstraction and painting process during the 1960s, Heron noted: ‘The only rule I follow while painting is this : I always allow my hand to surprise me (the lines of all the frontiers in my recent paintings are drawn-in in a matter of seconds) : also, I always follow impulse - for instance in the choice of colours; deliberation is fruitless. But this does not mean that every act connected with the painting of the picture is not deliberate : it is.’ (Heron quoted in exhibition catalogue, Patrick Heron: Recent Paintings, Paddington, Bonython Gallery, 1973, intro).