Ascomycota of their hosts. Owing to their long evolutionary history, the Ascomycota have evolved the capacity to break down almost every organic substance. Unlike most organisms, they are able to use their own enzymes to digest plant biopolymers such as cellulose or lignin. Collagen, an abundant structural protein in animals, and keratin—a protein that forms hair and nails—, can also serve as food sources. Unusual examples include "Aureobasidium pullulans", which feeds on wall paint, and the kerosene fungus "Amorphotheca resinae", which feeds on aircraft fuel (causing occasional problems for the airline industry), and may sometimes block fuel pipes. Other species can
Artificial nails polymer with "liquid monomer", usually ethyl methacrylate mixed with some inhibitor, forms a malleable bead. This mixture begins to cure immediately, continuing until completely solid in minutes. Another common material is acrylic gel, which contains photoinitiators that prevent its curing until exposed to either ultraviolet light within a certain wavelength. Some new techniques, too, have been invented, attempting to make obsolete the two outlined above. Dipping, for instance, involves painting nails with special primer and base coats, then repeatedly painting the nail with a clear coat and submerging it in powder. Nail products are available in a variety of colors