Pointillism was a post-Impressionist technique used between 1886 and the early 1900s. It involved applying small dots of primary colors to create secondary hues, giving the paintings a shimmering effect. Georges Seurat is considered the founder of Pointillism, developing the style in works like A Sunday Afternoon on the Island of La Grande Jatte. Other notable Pointillist artists included Camille Pissarro, Paul Signac, and Paul Gauguin.