Detail of the vault of the Chapel of the Holy Sacrament in St Peter’s, Rome, cartoon

This cartoon for the vault of the Chapel of the Holy Sacrament in St. Peter's Basilica, held in the Nationalmuseum in Stockholm, is a preparatory work for one of Cortona's most prestigious commissions — decoration in the greatest church in Christendom. Cartoons — full-scale preparatory drawings — were essential tools in fresco painting, transferred directly to the plaster surface. The survival of this cartoon provides invaluable insight into Cortona's working method for his Vatican commissions, preserving the design in a state closer to the artist's direct hand than the finished fresco.

The cartoon reveals Cortona's compositional thinking at full scale, with the dynamic arrangement of figures and celestial elements showing his mastery of illusionistic vault decoration. The drawing technique captures the energy and movement that would characterize the finished fresco.