Canvas 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, such as Jackson Pollock, Kenneth Noland, Francis Bacon, Helen Frankenthaler, Dan Christensen, Larry Zox, Ronnie Landfield, Color Field painters, Lyrical Abstractionists and others. Staining acrylic paint into the fabric of cotton duck canvas was more benign and less
Autumn Rhythm (Number 30) involved working on unprimed canvas laid on the floor of his studio, pouring paint from cans or using sticks, heavily loaded brushes and other implements to control a stream of paint as he dripped and flung it onto the canvas. At 17 feet wide and 8 feet high", Autumn Rhythm" is among Pollock's largest pictures. The creation of "Autumn Rhythm" was partly documented by Hans Namuth, who photographed Pollock at work over several months in 1950. According to art historian Monica Bohm-Duchen, Namuth's photographs lend insight to the sequence in which Pollock filled in the canvas, and the order in