Black and Red, 1968, is from Gordon Walters' most famous series of paintings based on the Maori motif called the koru. The koru series is now regarded by many discerning collectors and art critics as among the finest abstract painting produced in New Zealand. Walters began experimenting with the koru motif in the mid-1950s making small studies on paper in black and white, and colour. Initially these were much freer in design and handling than were the first large paintings he exhibited in the mid-1960s. He used a process of trial and error and experimentation in modifying, simplifying and geometricising the koru motif before he felt confident enough to commit it to a large painted format. Even then, he began by using hardboard supports that proved less than ideal for the smooth paint application he required to give his forms sharp definition and optimum contrast. By 1968, the year he painted Black and Red, Walters has dispensed with hardboard in favour of stretched canvas so that the PVA and acrylic paints he used could bond better with the support and not appear to be lying on top of it, as had happened with the hardboard. In this case, he carried the painted image around the sides of the stretcher to reinforce that effect. At the time, the early koru paintings seemed radical and were not immediately understood because there was little context for them. Interestingly, Colin McCahon was among the first private buyers of a koru work in 1966.

Black and Red belongs to the style known as geometric abstraction, a style not much practised in New Zealand then when more gestural and expressionistic handling was the norm. The obvious feature of geometric abstraction is the focus on a few precisely drawn forms, usually made with the help of instruments such as the ruler, square and compass. Significantly, Walters had a background as a layout artist and designer which familiarised him with working on a drafting table, rather than an easel, and being exact in his calculation of divisions of the surface and geometrical relationships between forms. He transferred his image to the canvas only after he had fully resolved it by preliminary studies, sometimes employing collage as well as drawings. All his koru paintings are based on a precisely drawn linear scaffolding. In painting the image, Walters applied his medium thinly with minimal signs of process. The red was applied evenly over the surface first and allowed to dry before the black was painted over it establishing the final forms. Some of the painters he admired, like Bridget Riley and Victor Vasareley, used assistants to paint their works, an option Walters never adopted. Rather he painstakingly hand-painted each work himself. This helps explain why the koru works are so rare and sought-after. Often he confined himself to monochrome because his imagery depends on the relationship between a few forms for its effect and this is maximised by the elimination of extraneous elements. More rarely he used colour, instead of black and white, as a means of coding and contrasting his forms. Here the visual counterpoint between light and dark which animates the image is brought out by the interplay of black and red. In the process, the tonal contrast is somewhat reduced and the image seems more stable to the eye than in some of the koru series where flicker and after images appear. Op artists sought to enhance these perceptual effects but Walters rarely did so and always kept a distance from Op. He preferred to set up an interplay between positive and negative readings of his forms, as here, where an alternation between black and red bands at the left is brought to a climax at the far right in the stacked clusters of koru 'bulbs'. These switch from red to black and back again with an insistent rhythmic beat. This substitutes for conventional spatial movement and gives the viewer a virtual equivalent that is based on our perception of how forms interact and appear to recede and advance.

During this period, Walters was arguably at his most inventive and experimental in his use of the koru motif. Not only does he introduce the unexpected bright red colour but he also pushes the koru 'bulbs' to the far right of his canvas giving a daring asymmetry to the image. The even, hard-edged focus of his painting gives maximum impact to the design. Although Walters' koru paintings are based on a Maori motif, he did not initially stress this aspect in his first exhibitions of them and reviewers did not make the connection. Titles like Black and Red stressed the formal properties of European abstraction rather than Maori references even though the black and red colouring, like the koru, can be sourced in Maori kowhaiwhai paintings. Soon afterwards, however, he began to use Maori titles often as a form of acknowledgement and sign of respect for his sources. By the 1990s, Walters' koru paintings became widely influential on both Maori and Pakeha contemporary painters and his series remains the benchmark of quality to which others must aspire.

Michael Dunn