Exemplifying Sirani’s masterful wash technique, this drawing is a preparatory study for her altarpiece in San Giacomo Maggiore, Castelfranco Emilia (Modena), signed and dated 1663. The painting was commissioned by the Bolognese nobleman Lorenzo Zagoni for his family chapel in the church. While an earlier brush sketch at the Louvre (Loisel, op. cit., no. 941, ill.) shows Saint Thomas hatless at right, in the present sheet his position is more prominent and his figure is more fully developed. Drawings by European women artists from this period are rare, but roughly one hundred by Sirani are known, making her the most prolific female draftsman of Early Modern Italy, despite her early death.