This particular sketch is chalk on paper, as with most of his drawings. It remains in the collection of the Ashmolean Museum, Oxford, UK. That institution also hold an extensive collection of other Raphael sketches.
1515 was a highly productive year for Raphael, and it is then that this particular drawing was completed. Most of the red chalk drawings from his career came between 1515 and 1518. In most cases he would use a darker chalk to add depth to his portraits.
Study drawings are often small and restricted to portable sketchbooks, as commonly used by JMW Turner, for example. This particular Raphael drawing, however, was a monumental two metres high by two metres wide. Its size, combined with its beauty means that it deserves to be treated as a high quality artwork in its own right, rather than just a piece of technical practice.
Studies of angels and God the Father, circa 1510-1520 is another related display of sketchwork. It is part of the British Royal Collection which has a considerable collection of prominent drawings from the Renaissance and Baroque periods. Some of the elements in that work correspond with Raphael's Disputá, with linked artworks found right across Europe.