Neo-impressionism is the name given to the post-impressionist work of Georges Seurat, Paul Signac, and their followers who, inspired by optical theory, painted using tiny adjacent dabs of primary color to create the effect of light. Neo-impressionism is characterised by the use of the divisionist technique (often popularly but incorrectly called pointillism, a term Paul Signac repudiated). Divisionism attempted to put impressionist painting of light and colour on a scientific basis by using an optical mixture of colours.

Instead of mixing colours on the palette, which reduces the intensity, the primary-colour components of each colour were placed separately on the canvas in tiny dabs so they would mix in the spectator’s eye. Optically mixed colours move towards white so this method gave greater luminosity. In other words, the Neo-Impressionists renounced the spontaneity of Impressionism in favor of a measured painting technique grounded in science and the study of optics.

Neo-Impressionists came to believe that separate touches of pigment result in a greater vibrancy of color than is achieved by the conventional mixing of pigments on the palette.

This technique was based on the colour theories of M-E Chevreul, whose De la loi du contraste simultanée des couleurs (On the law of the simultaneous contrast of colors) was published in Paris in 1839 and had an increasing impact on French painters from then on, particularly the impressionists and post-impressionists generally, as well as the neo-impressionists. Source: Tate.

Apart from Georges Seurat and Paul Signac, the list of well-known painters who adhered to neo-impressionism include Henri Matisse, Camile Pissarro, Henri Edmond-Cross and Jan Toroop.