‘Because my work is based on enquiry, studies are my chief method of exploration and my way into paintings.' Drawing lies at the heart of Bridget Riley's practice. As art critic Maurice de Sausmarez once argued, Riley sits in a long tradition of artists whose preparatory drawings ‘present so immaculate a cover to their creative machinations (for example Leonardo, Poussin, Degas and Seurat) that only knowledge of their preparatory material for paintings reveals their true stature and the full nature of their creative talent.'2 The artist herself has always recognised the importance of her works on paper and noted how gouaches such as Interactive Colour Study 2 are important aids to ‘accompanying me in a way parallel to my own experience in the studio.' Between 1980 and 1985, Riley began to focus solely on a linear format in her work. She chose the horizontal stripe as an effective vehicle for exploration into the optical interactions between different colours. The parallel lines of vibrant colour in Interactive Colour Study 2 vibrate against one another, forcing the surface of her painting to brim with the same vigour as kinetic energy. She explained that: ‘I do not select single colours but rather pairs, triads or groups of colour, which taken together act as generators of what can be seen through or via the painting. By which I mean that the colours are organised…so that the eye can travel over the surface in a way parallel to the way it moves over nature. It should feel caressed and soothed, experience frictions and ruptures, glide and drift. Vision can be arrested, tripped up or pulled back in order to float free again.' In the Interactive Colour Studies, Riley turns to an expanded palette of pink, orange, blue and green. The different hues interact to produce a cool and bright atmosphere. Hints of lilac and green catch the eye with a spontaneity that suggests the effervescent optical effects of nature. Here, the lack of black, white or grey allows a rapidity to the chromatic interactions, prohibiting any ‘intermediary' zones. Despite the formal primacy of these colour studies, aspects of nature, particularly its state of perpetual flux, are striking. Riley has frequently referenced her early childhood experiences walking along the cliffs in Cornwall, her mother teaching her the pleasures of looking, as the formation of her entire subsequent visual life. Lyrical and intense, these studies evoke her memories of the sea and coastline – it's thrilling contrasts, unexpected chromatic shifts, and ever-changing patterns in the light, encapsulating ‘the entire, elusive, unstable, flicking complex' of nature itself.