Pointillism is the technique pioneered by Georges Seurat and Paul Signac in the 1880s, in which tiny dots of pure, unmixed colour are placed side by side on the canvas and blend optically when seen at the correct viewing distance. The method was grounded in scientific colour theory — particularly the work of Ogden Rood and Michel Eugène Chevreul — which argued that optical mixing produces greater luminosity than physical pigment mixing. Seurat called his approach 'Chromoluminarism' or 'Divisionism'. A Sunday on La Grande Jatte (1884–86), painted with extraordinary patience over two years, is its masterpiece. The technique was highly influential: Signac's promotion of it through writing and example directly shaped Matisse's early experiments with pure colour, and through Matisse, the entire Fauvist movement.