Andrea del Sarto made these drawings as studies for figures in an unfinished painting in the Palazzo Pitti in Florence. On the recto, with strong, sure strokes, he worked out the musculature of the kneeling apostle who appears in the painting's left foreground. On the verso, the standing nude figure with drapery provides the pose for Saint Thomas. Of the two heads later crossed out by the artist, the one at the upper right resembles the apostle on the recto. Del Sarto used these poses again in other paintings.
Del Sarto's working process of making a series of preparatory drawings for each of his paintings became a model for other artists of the 1500s. He began by quickly jotting down a first idea, then, as in the kneeling figure on the recto, he made studies of individual figures, checking them against a live model. He also used sculpture as a source. Del Sarto then developed the initial composition into a sequence of studies drawn in rapid, soft strokes of black or red chalk, which led to the final version for the painting. The final cartoon was transferred to the wall or panel.