Witches' Sabbath (The Great He-Goat) whose full-length portrait appears in the same series. As with the other "Black Paintings", Goya began with a black background which he painted over with lighter pigments, then with broad, heavy brushstrokes of grey, blue and brown. The darker areas were achieved by leaving the black under-paint exposed; this is most obvious in the figure of the Devil. Like the other works in the series, "Witches' Sabbath" is worked up through heavy, slashing brushstrokes. The plaster was underlaid with thick carbon black before the paint was applied in hues of white lead, Prussian blue, vermilion of mercury, and crystals of
Witches' Sabbath century. The "Canon Episcopi" forwards the Christian doctrine that things of this nature were false delusions and did not occur in reality. "Errores Gazariorum" later evoked the Sabbat, in 1452. Helping to publicize belief in and the threat of the Witches' Sabbath was the extensive preaching of the popular Franciscan reformer, Saint Bernardino of Siena (1380–1444), whose widely circulating sermons contain various references to the sabbath as it was then conceived and hence represent valuable early sources into the history of this phenomenon. Some allusions to meetings of more than one witch and possibly other demons are made in the