Using Encaustic painting means you work with heat, so wax must be melted, and synthetic haired brushes, can melt if the temperature is a bit high. Natural brushes, never melt unless you use very high temperatures.Metal tools and special brushes ( can be used to shape the paint before it cools, or heated metal tools can be used to manipulate the wax once it has cooled onto the surface). On Oil it makes no difference, just that the synthetic haired brushes are a bit harder to use, while natural brushes are softer... This technique was notably used in the Fayum mummy portraits from Egypt around 100-300 AD, in the Blachernitissa and other early icons, as well as in many works of 20th-century North American artists, including Jasper Johns, Tony Scherman, and Fernando Leal Audirac. Kut-kut, a lost art of the Philippines, implements sgraffito and encaustic techniques. It was practiced by the indigenous tribe of Samar island around 1600 to 1800.Artists in the Mexican muralism movement, such as Diego Rivera and Jean Charlot sometimes used encaustic painting. They always use natural hair brushes....
