Besides an artist's personal notes or treatises on the art of the period, the systematic arrangement of separate colors and mixtures on the palette, which the painter prepared before he began his work, is of the utmost importance when studying artists' painting procedures. Such palettes can be found in portraits or self-portraits where the palette is held in the hand with the rows of colors and tints clearly visible. When submitting their paintings, such as self-portraits or portraits of fellow artists, most painters of the French Academy display with a certain pride the carefully prepared palette. One of the most important portraits of this kind is the portrait of Vien (the teacher of Jacques-Louis David) by Duplessis, 1785 (Louvre), where the setting of the palette is depicted with the greatest care and meticulous attention to detail and accuracy. The palette with its patches of color almost has the quality of still-life deception. Under the influence of the strict rules of the French Academy or of professional painters' guilds, as in Switzerland, it became fashionable to display the prepared palette not only on self-portraits but also on many still-life paintings in order to show the tools of the painter.1