London’s Tate Modern is home to some gorgeous Bridget Riley canvases, huge rectangles of rhombic mosaics, in shifting colour that one can stand in front of and lose oneself in. A fifteen minute stroll west along the embankment, the Hayward Gallery seems to have all of them and then carpet bombs the place with a massive selection of the artist’s extraordinary, life-long output. The gallery’s airy spaces are filled with a veritable cornucopia of her work, spanning from 1947 to today. It is an authoritative exhibition, showing the artist’s 70-year development, a grounded and playful exploration of human perception.

Riley’s black and white phase, to which she has often returned for further exploration, tested the contention that “certain elements within a particular situation remain constant” whilst “others precipitate the destruction of themselves by themselves”. Try it. Stand in front of Movement in Squares or Blaze 1 and try not to see a monochrome vision of Kubrick’s stargate where what is absolutely static on the canvas appears to be moving on the retina.

The scale of canvas which triggers this doesn’t seem to matter. The exhibition presents several wall-sized paintings — in colour and in black-and-white — and one can advance towards them or retire back from them to engage the peak of this effect. The photographs I took to use on this post are shrunken versions of their real-life equivalents and even they unleash the same degree of retinal disturbance. (By the way, each has a larger version for you to call up with a click.) One is reminded of the prehistoric BBC test card F as seen on a diminutive black-and-white TV, fuzzed up with the famous moiré pattern.

1/10 Movement in Squares by Bridget Riley, 1961
Movement in Squares, synthetic emulsion on board, by Bridget Riley, 1961. 109.20 x 109.20 cm.
2/10 Blaze 1 by Bridget Riley, 1962
Blaze 1, synthetic emulsion on board, by Bridget Riley, 1962. 109.20 x 109.20 cm

So many aspects of this exhibition are glorious. Top of the list is being able to get up close and personal with these canvases. To close in on them and discover that what you thought was a triple-colour group of parallel lines, black sandwiched with blue and red, is in fact a black line sandwiched by bands of colour that intermittently narrow to cause a pulsing effect, is a small revelation, one that plants a seed about how a Riley painting works.

3/10 Cascando by Bridget Riley, 2015
Cascando, acrylic on polyester, by Bridget Riley, 2015. 140.5 x 459.2 cm

Her Cascando, at four and a half metres long, is a series of (mostly) triangles. As your eye roves around this expanse of black and white, a tug-of-war unfolds as to whether you are looking at black triangles on a white background, or vice versa. And at what point does the one change over into the other? Confounding this, as a visual digression, an interjection, is the fact that many of these triangles have one side which is curved — and these curves are either concave or convex. Trying to nail it all down is nearly impossible as every attempt to count the frequency of an individual pattern is frustrated by the shifting position of each component. Yes, “destruction of themselves by themselves” indeed!

4/10 Black and White at the Bridget Riley Exhibition at the Hayward Gallery, November 2019
Black and White at the Bridget Riley Exhibition at the Hayward Gallery, November 2019
5/10 Stripes and Diagonals at the Bridget Riley Exhibition at the Hayward Gallery, November 2019
Stripes and Diagonals at the Bridget Riley Exhibition at the Hayward Gallery, November 2019
6/10 Curves at the Bridget Riley Exhibition at the Hayward Gallery, November 2019
Curves at the Bridget Riley Exhibition at the Hayward Gallery, November 2019

The second thing one notices in the detail is the utter clarity of these lines. Where black meets white is the crispest possible line, the sort than anyone dabbling with pen and ink or watercolour will aspire to and rarely achieve. There are absolutely no spodges, no percolating or leaching from one side of the line to the other. The same is true in colour, that borders between one colour and its adjacent colour are 100% crisp, again irrespective of scale. It is utterly beguiling. It is all the more important as it is on these colour boundaries that our vision adds its own shades and progressions where none exist on the canvas. This demonstrates Riley’s contentions in the Stripes and Diagonals work that “you can never see colour by itself, it is always affected by other colours”. These colour canvases of hers play with this interrelationship.

7/10 High Sky, oil on canvas, by Bridget Riley, 1991
High Sky, oil on canvas, by Bridget Riley, 1991. 170 × 230 cm

Riley’s rhomboid paintings test this further by combining the dynamism of her black-and-white work with her work on colour paradox. High Sky plays with the expectation and disappointment of perceived pattern. These are large canvases, over two metres across and, standing back from them, one wrestles with the rhomboids, trying to hold them in place long enough to establish what their sequence intervals might have been. Some protrude out of the space allocated to them, defying what might have been their assigned role. They seem to have forced themselves out of their starting point and extended themselves towards the bottom-left of the canvas. Others appear to have landed in the wrong place and sit uncomfortably adjacent to others of the same colour, interlopers in the geometric framework, confounding an orderly distribution of colour.

8/10 Study for stripes and diagonals by Bridget Riley
Study for stripes and diagonals by Bridget Riley

The Hayward has one of their upstairs galleries devoted to Riley’s study of how these visual effects operate. It is exquisite, demonstrating a vigorous work ethic. Large scale preparatory drawings, tests and analyses are presented, many with detailed annotations. One gets a feel for the process whereby she combined analysis with judgement, leading to her signing off a blueprint from which her assistants could then execute the final painting.

9/10 Study work by Bridget Riley, 1967
Study work by Bridget Riley, 1967

Also included was a section on Riley’s early work exploring Georges Seurat’s pointillism, bringing a more scientific approach to painting with colour. Her copy of his Le Pont de Courbevoie helped her appreciate how an apparently fragmented image can be assembled whole in the viewer’s mind. It gave her “a sense of the viewer’s importance as an active participant”.

10/10 Study of Seurat's Le Pont de Courbevoie by Bridget Riley, 1959
Study of Seurat’s Le Pont de Courbevoie by Bridget Riley, 1959

This is a glorious exhibition, a fitting tribute to Britain’s inspirational op-art doyenne. It runs at the Hayward Gallery until 26th January 2020.