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
Portrait of a Lady Known as Smeralda Brandini clients for many years, is likely that Cartwright has confused Viviano with his son Michelangelo (Michele) because in 1475, the year of the tournament of La Giostra to which she refers, Michele was only 18 years old and his father was much better known. Art historians note new features in the composition: "earlier Florentine portraits were in profile. The woman's three-quarter pose, with her hand on the window frame, was Botticelli's own invention". The portrait is thought to be the first example of a three-quarters pose in Florentine portrait painting. "By abandoning the profile pose traditionally used in depictions of