Most everyone is familiar with Georges Seurat painting "Sunday Afternoon on the island of La Grande Jatte". With that painting he initiated the neo-impressionistic art movement which altered the direction of modern art during the later part of the 19th century. Along with Paul Signac, Seurat painted in a technique called chromoluminarism where the color is broken down into its basic elements and is then painted in small dots to create the color we see from a distance. It's quite time consuming as one can imagine and the 82X121 inch "Sunday Afternoon.." reportedly took two years.
I do love the chromoluminarist style, but it is his sketches and drawings that makes me think of him as a genius. The dark conté crayon covers every square inch of the paper and its in the slight contrasts in density that the shapes appear, the drawings lack detail but they are full of life.
If you like Seurats drawings check out this book with lots of amazing pictures.