Skiagraphia

Skiagraphia is a painting technique developed by Ancient Greek painter Apollodorus, used to create shadows in an image.

Skiagraphia is often described as a hatching technique used to create the illusion of forms through shading. The shading is created by the use of curved lines, either by the use of hatching or cross-hatching. Within this same approach, painters can use different colors to add shade to an area.

Archaeologist Eva Keuls, using passages from Aristotle, suggested that "skiagraphia" was a technique that utilized patches of color that blend from afar, similar to the neo-impressionist paintings of Georges Seurat, but this is disputed by Elizabeth G. Pemberton, who instead suggests that the passages from Aristotle are only in relation to shade and not color.