The original autograph manuscript is by Pacheco, painter, teacher and father-in-law of Velázquez. The work includes 56 portraits drawn with red and black pencils, on a shadowed background, stuck on the pages that would be bound later on, in which there is a biographical sketch.
This book is one of the most beautiful in the Golden Age, not only because of the excellent quality of the drawings, but also the exceptional calligraphy, and the painter was always concerned about it and even stated in his will that the portraits should be preserved together.