The First Layer of a master painting....

The First Layer: reconstruction of canvas of the master painting 'Saint John in the Wilderness' 
research and reconstruction : Lab O 
Saint John in the Wilderness: Observations on Technique, Style, and Authorship
Frank Zuccari, Zahira Véliz and Inge Fiedler
Art Institute of Chicago Museum Studies
Vol. 31, No. 2, Conservation at the Art Institute of Chicago (2005), pp. 30-45+105-108