Canvas is an extremely heavy-duty fabric used for making sails, tents, marquees, and other functions where sturdiness is required. It is also popularly used on fashion handbags.
Canvas as an artistic material
Artists use small (or sometimes much larger) pieces of canvas as a base for their works of art. This canvas is stretched across a wooden frame called a stretcher, and is coated with gesso before it is to be used (although some modern artists, such as Francis Bacon and Helen Frankenthaler, sometimes paint onto the bare, unprimed canvas). Early canvas was made of linen, a sturdy brownish fabric of considerable strength.
In the early 20th century, cotton came into use. Cotton, which stretches more and has an even mechanical weave, is less preferred than linen by the professional artist. The considerable price difference, however, prompts many beginners, and even mid-level artists, to choose cotton over linen. One can also buy small, pre-prepared canvases which are glued to a cardboard backing in the factory and precoated. However, these are only available in certain sizes, and are not acid-free, so their lifespan is extremely limited. They are usually used for quick studies. Pre-gessoed canvases on stretchers are also available. Professional artists who wish to work on canvas usually prepare their own canvas in the traditional manner.
One of the most outstanding differences between modern painting techniques and those of the Flemish and Dutch Masters is in the preparation of the canvas. "Modern" techniques take advantage of both the canvas texture as well as those of the paint itself. A novice artist often finds it nearly impossible to approach the realism of such classic art, despite skill in applying the paint. In fact, Renaissance masters took extreme measures to ensure that none of the texture of the canvas came through. This required a painstaking, months-long process of layering the raw canvas with (usually) lead-white paint, then polishing the surface, and then repeating. The final product had little resemblance to fabric, but instead had a glossy, enamel-like finish. Though this may seem an extreme measure to the modern painter, it is crucial if photographic realism is the end goal.
With a properly prepared canvas, the painter will find that each subsequent layer of color glides on in a "buttery" manner, and that with the proper consistency of application (fat over lean technique), a painting entirely devoid of brushstrokes can be readily achieved.