Georges Seurat (1859–1891), Poseuses (1886-8)

All painting is a form of optical illusion, but pointillism, the technique Seurat pioneered in the 1880s, aims to deconstruct the act of seeing itself. He was keenly interested in how the eye interprets colour, and drawn to the theories of the chemist Michel Eugène Chevreul. Chevreul explored the workings of colour after he became director of the historic Gobelins tapestry factory in 1824.

He observed that two colours, when placed near to one another, would look like a third colour when viewed from a distance, and called the effect ‘simultaneous contrast’.

Chevreul advised painters to incorporate such colour contrasts into their work, referring to its affect as ‘harmony’; Seurat was interested in the way it evoked emotion. This visual manifestation of emotion as a sense of blurred vibration, is part of what makes his works so captivating. His Poseuse debout, de face (1886), serves as illustration in this argument. See how the particulate blue light floats in front of the model’s body, colouring her skin, but also catching her up in a swirl of atmosphere, a little cyclone of vibrating beingness. Although the model stands in a studio, the colourful aura reminds one of the air on a beach at dusk, when one can almost see the negative ions shimmer, all forms revealed as a swarm of atoms, electric.