Cadmium red and scarlet were frequently occurring colours in Patrick Heron’s palette. He often created a sense of visual tension by juxtaposing prismatic colours, and Reds : 2 Green Lines : May 12 : 64 uses a narrow range of warm earth colours—red, orange, brown—against which the titular ‘2 green lines’ register with a force disproportionate to their modest presence on the paint surface. This work was painted shortly before the artist began to use clearly defined frontiers between neighbouring colours, and to employ more polarised colour contrasts, which started to appear in his work in the autumn of 1964.

The painterly freedom of Reds : 2 Green Lines : May 12 : 64 was fostered in part by the modest scale of the canvas. Unlike larger canvases made around the same time, in which paint was applied thinly and evenly, this modest rectangular support enabled Heron to explore a more varied application of paint. The execution is markedly inventive. The ‘2 green lines’, applied with single strokes, have a substantial impasto that registers the texture of the brush, and they appear clean and sharp against the underlying area of brown. The starburst of orange colour at the upper right-hand corner was painted wet-on-wet with a wide brush, and the energetic action of the brush is richly apparent. This area of orange and brown paint is in turn loosely ringed by a soft-edged square of black paint, which was applied by a single application of a loaded brush. Autographic qualities were less important to Heron’s artistic trajectory than unmediated effects of pure colour, and he came to position himself as a colour field painter rather than an action painter. Yet the texture and handling of paint in Reds : 2 Green Lines : May 12 : 64 show that the activity of execution—far more than the mere plotting of colour schemes—was a vital aspect of his work.

Heron was represented by the Waddington Galleries and his solo exhibition there, held in November and December 1964, included works of a standard size. Paintings measured between 30 by 40 inches and 60 by 84 inches. Nothing the smaller size of Reds : 2 Green Lines : May 12 : 64, measuring 10 by 14 inches, was included in the exhibition. Another painting completed the day after this work was included in that exhibition, Mainly Greens : May 13, 1964, which measured 30 by 40 inches. Another small-scale work was completed on the same day, Small Crimson : May 12th 1964, which measured 12 by 10 inches and was exhibited in a joint exhibition held with Bryan Wynter at Hume Tower, Edinburgh.

This painting was handled by Waddington Galleries, London, who assigned it the stock number 7579, and it was acquired there by the late owner in December 1964.