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
Jackson Pollock technique of pouring and dripping paint is thought to be one of the origins of the term action painting. With this technique, Pollock was able to achieve a more immediate means of creating art, the paint now literally flowing from his chosen tool onto the canvas. By defying the convention of painting on an upright surface, he added a new dimension by being able to view and apply paint to his canvases from all directions. One definitive influence on Pollock was the work of the Ukrainian American artist Janet Sobel (1894–1968) (born Jennie Lechovsky). Peggy Guggenheim included Sobel's work in