Michelangelo sought to impress with a full-out display of his virtuosity in terms of poses, splashes of color, and creamy drapery. Among his personages on the Sistine Chapel ceiling, there is a group of sibyls, who were prophets from Greek and Roman mythology. He had to compete with the frescoes on the sides of the Chapel that were painted by other illustrious artists of the time, so he resorted to the most bold techniques he could think of. One of his main concerns was to have the finest quality pigment available, and, at the time, pigment production was a complex art done mostly by apothecaries and friars. The blues, whites, and ochres came from clays found in Italy, while the ultramarine was made from lapis lazuli from Afganistan, and the tone depended on how finely or coarsely each one was ground.
The pagan origins of the sibyls were legitimized by their prophesies of Christian events, but there was also a general fascination with the Greek and Roman past and prophesies. Virgil’s Eclogues , for example, include a prophesy were the Cumaean Sibyl hints at a return to a golden age, which gave fuel to contemporary “prophets” to laud the pope’s cultural endeavors. Michelangelo, on the other hand, seems to depict them only in terms of their femininity (or lack thereof, in one case) as though they were models for his decadent drapery. He even pokes fun at the contemporary “prophets” by giving his Cumaean Sibyl particularly rough musculature, while one of the children makes a “fig” gesture in her direction. No one would have seen this slight signal of disrespect from down below, and Michelangelo used that to his advantage to include many such tongue-in-cheek references throughout his work in the Chapel.