Canvas is one of the most commonly used supports for painting. It consists of strong unbleached cloth, usually of hemp or flax, fixed over a wooden framework. Canvas is normally primed before being painted on. Before the 19th century, large-scale canvases were always made of pieces joined together.
The earliest surviving canvases date from the late 14th century. Wood panels were previously the most common support, but are heavier and so less portable. The evolution of the use of canvases to some extent parallels that of oil paint; however it was also the usual support for glue-size paintings produced in great quantity in the Netherlands, although relatively few have survived.
The earliest painting on canvas in the National Gallery is the 'Madonna of Humility' by Lippo di Dalmasio, which may have been a confraternity banner.