Certain artists, especially in Bologna and Venice, steeped sticks of charcoal in oil to obtain a denser, richer, and more permanent line. Guercino (Giovanni Francesco Barbieri, (Cento 1591-Bologna 1666) was especially fond of this technique, and Giacomo Cavedone (Sassuolo [Modena] 1577- Bologna 1660) especially favored oiled charcoal heightened with white chalk on dark brown paper for head studies.