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
The Joy of Painting old instructor John Thamm, and many others. Within the 30-minute program, Ross graphically ran the colors across the screen (this was not done in earlier seasons), as he turned the blank canvas into an imaginary landscape, using the wet-on-wet oil painting technique, in which the painter continues adding paint on top of still-wet paint rather than waiting for each layer of paint to dry. Combining this method with the use of two-inch and other types of brushes, as well as painting knives, allowed him to paint trees, water, clouds, and mountains in a matter of seconds. Each painting would start