Everything about canvas：
Canvas has become the most common support medium for painting, custom printing, replacing wooden panels. It was used from the 14th century in Italy, but only rarely. One of the earliest surviving oils on canvas is a French Madonna with angels from around 1410 in the Gemäldegalerie, Berlin. Its use in Saint George and the Dragon by Paolo Uccello in about 1470, and Sandro Botticelli's Birth of Venus in the 1480s was still unusual for the period. Large paintings for country houses were apparently more likely to be on canvas, and are perhaps less likely to have survived. It was a good deal cheaper than a panel painting, and may sometime indicate a painting regarded as less important. In the Uccello, the armour does not use silver leaf, as other of his paintings do (and the colour therefore remains undegraded). Another common category of paintings on lighter cloth such as linen was in distemper or glue, often used for banners to be carried in procession. This is a less durable medium, and surviving examples, in distemper on linen are rare, and often rather faded in appearance.
Panel painting remained more common until the 16th century in Italy and the 17th century in Northern Europe. Mantegna and Venetian artists were among those leading the change; Venetian sail canvas was readily available and regarded as the best quality.
Canvas is typically stretched across a wooden frame called a stretcher and may be coated with gesso before it is to be used; this is to prevent oil paint from coming into direct contact with the canvas fibres, which will eventually cause the canvas to decay. A traditional and flexible chalk gesso is composed of lead carbonate and linseed oil, applied over a rabbit skin glue ground; a variation using titanium white pigment and calcium carbonate is rather brittle and susceptible to cracking. As lead-based paint is poisonous, care has to be taken in using it. Various alternative and more flexible canvas primers are commercially available, the most popular being a synthetic latex paint composed of titanium dioxide and calcium carbonate, bound with a thermo-plastic emulsion. Many artists have painted onto unprimed canvas. Staining acrylic paint into the fabric of cotton duck canvas was more benign and less damaging to the fabric of the canvas than the use of oil paint. In 1970 artist Helen Frankenthaler commented about her use of staining:
When I first started doing the stain paintings, I left large areas of canvas unpainted, I think, because the canvas itself acted as forcefully and as positively as paint or line or color. In other words, the very ground was part of the medium, so that instead of thinking of it as background or negative space or an empty spot, that area did not need paint because it had paint next to it. The thing was to decide where to leave it and where to fill it and where to say this doesn't need another line or another pail of colors. Its saying it in space.
Early canvas was made of linen, a sturdy brownish fabric of considerable strength. Linen is particularly suitable for the use of oil paint. In the early 20th century, cotton canvas, often referred to as "cotton duck," came into use. Linen is composed of higher quality material, and remains popular with many professional artists, especially those who work with oil paint. Cotton duck, which stretches more fully and has an even, mechanical weave, offers a more economical alternative. The advent of acrylic paint has greatly increased the popularity and use of cotton duck canvas. Linen and cotton derive from two entirely different plants, the flax plant and the cotton plant, respectively.
Gessoed canvases on stretchers are also available. They are available in a variety of weights: light-weight is about 4 oz (110 g) or 5 oz (140 g); medium-weight is about 7 oz (200 g) or 8 oz (230 g); heavy-weight is about 10 oz (280 g) or 12 oz (340 g). They are prepared with two or three coats of gesso and are ready for use straight away. Artists desiring greater control of their painting surface may add a coat or two of their preferred gesso. Professional artists who wish to work on canvas may 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. 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.
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 achieved. A warm iron is applied over a piece of wet cotton to flatten the wrinkles.
Canvas can also be printed on using offset or specialist digital printers to create canvas prints. This process of digital inkjet printing is popularly referred to as Giclée. After printing, the canvas can be wrapped around a stretcher and displayed.