Raffaello Sanzio, or Raphael, together with Michelangelo and Leonardo da Vinci, forms the traditional trinity of great masters of Renaissance. He was one of the finest masters of drawing in the history of art. The completing of a huge number of studies in a diversity of techniques was Raphael's typical practice. He first made rapid sketches, and then polished them for transfer. The number of his existing drawings is over 400, but this is only a small part of the amount he produced. There was a diversity of media and techniques in his time, and he explored all of them. Raphael acquired ability in the use of silverpoint, in which the metal tip of a stylus is worked on a prepared ground applied to the paper. He first used pen and ink broadly after 1505. Most Raphael drawings are to a certain extent precise—even initial sketches with naked outline figures are carefully drawn. His drawings may be lack the freedom and energy of Leonardo's and Michelangelo's sketches, but are visually almost perfect.