the background of the Renaissance and its leading personali- ties. And this will prove invaluable in helping us to under- stand how the evolution of painting and drawing came about at this time, for it was largely this new and vital force, developing suddenly in all fields of culture, that urged the many technical advances brought about in painting since the time of Van Eyck.
In the preceding chapters we have traced these developments to the individual artists who were, so far as we can tell, actually responsible for the basic changes in medium. First, following the work of the traditional tempera schools, came Jan Van Eyck's discoveries, bringing great new possibilities to the existing painting technique; and next came Antonello da Messina who invented a medium for the first process entirely in oil. Then the discovery was made of the ingenious process which lightened the color of Antonello's medium, an innovation we attribute to Leonardo Da Vinci whose further improvement of the medium, through the addition of wax, made it possible for it to be used for large areas. During the same period, Giorgione converted the pas te medium into the liquid black oil and used it with wax for the first really successful large scale painting. Titian (who in his youth collaborated with Giorgione) and Tintoretto each developed variations oftheir own on the same medium-Titian with the use of the velatura and glaze, and Tintoretto with a broader method that allowed the greatest speed and efficiency.
The formulas for each of these successive mediums have been reconstructed separately* for practical usage by the reader, and now we must pass to that great master who, a hundred years later, made alI things technically possible in painting.
.See the second section of this book.