In 1568 the artist and art historian Giorgio Vasari wrote in his Lives of the Artists that the Venetians did not make preliminary drawings for their paintings. The recent use of infrared reflectography to study Venetian paintings has forced a revision of this view. Infrared reflectograms, which allow us to peer beneath the paint surface, reveal that Venetian painters often drew directly on the canvas instead of making numerous studies on paper.
The infrared images show that Giorgione and Titian used fluid brushstrokes to indicate the placement and shape of the figures and their settings. Such drawings provided only a guideline; x-rays of paintings, called x-radiographs, expose underlying paint layers which demonstrate that the creative process continued in the course of painting. Artists experimented with different poses and compositions, adding and eliminating details, such as the exotic headdress in Giorgione's Three Philosophers, which was painted out in the final composition.