Jean-Paul Riopelle to abstract expressionism), in which he used myriad tumultuous cubes and triangles of multicolored elements, facetted with a palette knife, spatula, or trowel, on often large canvases to create powerful atmospheres. The presence of long filaments of paint in his painting from 1948 through the early 1950s has often been seen as resulting from a dripping technique like that of Jackson Pollock. Rather, the creation of such effects came from the act of throwing, with a palette knife or brush, large quantities of paint onto the stretched canvas (positioned vertically). Riopelle's voluminous impasto became just as important as color. His
Canvas 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