Claude Tousignant has made measurable contributions to abstract painting since his earliest works of the 1950s. Now in his eighties, Tousignant’s legacy has enhanced understandings of colour reception to illuminate optical colour interaction and the elegiac beauty of large fields of colour for the eye’s enjoyment and study. Commencing in the 1960s, his use of the circle marked a crucial moment wherein he saw the possibilities of creating unique optical experiences. It was Tousignant’s circular transformers, gong and accelerator paintings of the mid-1960s which amplified his engagement in the optical effects of colour interaction through experimentation with concentric rings of colour. In the 1970s, Tousignant further challenged his painting practice when he began working in the diptych format with both the circle and the half-circle and began moving towards a minimalist approach. As seen through this focused exhibition of three major works in the AGW collection, Tousignant’s practice is a wide-ranging experience of colour and colours, and shape and shapes, revealing much about the power of the visual experience. His view is so seemingly simple in painterly rendering yet so infinitely complex to the human eye and its ability to process what is reality and what is illusion.