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 Ghost of a Flea the work is in relatively poor condition, partly due to the technique employed by Blake. Areas of the surface have cracked and dulled with age. Although Blake was singular in his ability to directly transcribe visions onto canvas or paper, a number of visual and literary sources can be detected in this work. The art historian Hope Werness suggested that "The Flea" may be inspired by a 1665 work by early microscopist Robert Hooke (1635–1703), whose "Micrographia" includes a drawing of a flea microscopically observed. Comparisons have been made to Henry Fuseli's monstrous imps, while the image of the flea