For scholars, this work is an example of Leonardo's experiments on the theme of the so-called shoulder portrait, with the view from the back and the face turned towards the observer, the result of the teachings of Leonardo's master, Andrea del Verrocchio, on how to portray a figure in motion, taking it from various points of view. Dating from around 1483-1485, it is probably a preparatory study for the Angel of the Virgin of the Rocks, a pictorial work whose first version is kept in the Louvre in Paris, the second in the National Gallery in London. The drawing has also been identified with Cecilia Gallerani, the young woman loved by Ludovico Sforza and represented in the painting preserved in Krakow, The Lady with an Ermine. In 1952, on the occasion of the fifth centenary of Leonardo's birth, the American art historian Bernard Berenson called the portrait the most beautiful drawing in the world.

Although it is likely a study of a character datable to Leonardo's Milanese years (around 1490), this drawing is universally recognized as a self-portrait of Leonardo da Vinci, almost the symbolic icon of the Renaissance artist, expression of his genius and talent applied to most diverse fields of knowledge. The essential features of Leonardo's face, in particular his beard and long hair, are also testified by iconographic and written sources. The drawing was unknown until the early nineteenth century, when it was replicated for the first time in a volume dedicated to the Last Supper in Milan and identified as a "self-portrait". According to recent studies it would be a work carried out by the now sixty-year-old master, shortly before or shortly after his departure for France (Amboise Castle), where he died in 1519.

The drawing has been identified as a preparatory study for the figure of the Cumaean Sibyl in the vault of the Sistine Chapel, the great masterpiece created by Michelangelo between 1508 and 1512. It is undoubtedly a study from life by a male model, of which Michelangelo used it to elaborate the dynamism and the expressive form of the face. In the transition to the fresco, all that remained was to add the turbaned headdress that crowns the Sibyl in the fresco in the Vatican chapel. The sheet, a graphic masterpiece of the Renaissance, is a very important testimony of the artist's working method, who used drawing as a means to achieve the artistic goals he proposed.

The drawing is probably a preparatory work for a detail of the Baptism of Christ frescoed by Perugino in the Sistine Chapel between 1481 and 1482 commissioned by Pope Sixtus IV. The drawing, consisting of a nude young man in the foreground next to an old man in the background with heavy oriental robes and headdress, has few variations compared to the painted version. The artist, in whose workshop the young Raphael was trained, manifests a conception of space based on an extreme compositional balance, derived from the assimilation of Piero della Francesca's poetics, but also from the attendance of Verrocchio's workshop in Florence. The undoubted quality of the stroke expresses a still fully fifteenth-century sensitivity.

"He enriched the art of painting with that entire perfection that the figures of Apelles and Zeusi had in ancient times": with these words Vasari consecrates Raphael to the apex of Renaissance art for inventiveness and naturalistic grace, equal to those of the ancients. The design was attributed to the early period, still marked by the influence of Perugino, his first true teacher, and shows a great executive refinement in the pieces of the head and hands. The sheet depicts a seated young man, dressed in the fashion of the time while playing the lute, probably a musician angel destined to be part of some sacred subject composition. It is undoubtedly a preparatory drawing even if the figure of the young man has not been associated with any pictorial work by Raphael. The artist from Urbino was one of the greatest and most prolific designers of the time: over 400 drawings of him survive and many others have been lost over the centuries.

The volume, probably set up at the beginning of the seventeenth century, contains seventy-five plates concerning almost exclusively marine, freshwater or Mediterranean coastal animals: Fish, Reptiles, Mammals, Crustaceans, Molluscs and Echinoderms. The organisms represented, sometimes more than one per panel, with rare repetitions, are very numerous and the large drawings are done in tempera on a cardboard cut out and glued to the album sheets. The drawings tend to reproduce the original dimensions of the species for which the sheets have in many cases been folded several times on themselves to reduce their excessive width (up to more than 3 meters). The artistic quality is generally good, although the designers, probably more than one, have often not reported important anatomical or chromatic details, useful for a certain identification of the species. The ittionimi used are mostly Nice, often accompanied by Portuguese names, partly still valid today. Except for two figures, representing a fantasy "fish" and a non-existent monk fish, all the illustrations refer to existing species. The reasons behind the creation of this volume are not clear, from which many of the banal species of fish, molluscs and crustaceans of the north-central Mediterranean Sea are missing, while the drawings of the Nile crocodile and the Uromastice refer beyond any reasonable doubt , to specimens present in the ducal collections of living animals. The work was most likely present in the library of the Grand Gallery of Duke Carlo Emanuele I of Savoy, based on the inventory of 1659.

The volume, probably set up at the beginning of the seventeenth century, contains seventy-five plates concerning almost exclusively marine, freshwater or Mediterranean coastal animals: Fish, Reptiles, Mammals, Crustaceans, Molluscs and Echinoderms. The organisms represented, sometimes more than one per panel, with rare repetitions, are very numerous and the large drawings are done in tempera on a cardboard cut out and glued to the album sheets. The drawings tend to reproduce the original dimensions of the species for which the sheets have in many cases been folded several times on themselves to reduce their excessive width (up to more than 3 meters). The artistic quality is generally good, although the designers, probably more than one, have often not reported important anatomical or chromatic details, useful for a certain identification of the species. The ittionimi used are mostly Nice, often accompanied by Portuguese names, partly still valid today. Except for two figures, representing a fantasy "fish" and a non-existent monk fish, all the illustrations refer to existing species. The reasons behind the creation of this volume are not clear, from which many of the banal species of fish, molluscs and crustaceans of the north-central Mediterranean Sea are missing, while the drawings of the Nile crocodile and the Uromastice refer beyond any reasonable doubt , to specimens present in the ducal collections of living animals. The work was most likely present in the library of the Grand Gallery of Duke Carlo Emanuele I of Savoy, based on the inventory of 1659.

The volume, probably set up at the beginning of the seventeenth century, contains seventy-five tables concerning almost exclusively marine, freshwater or Mediterranean coastal animals: Fish, Reptiles, Mammals, Crustaceans, Molluscs and Echinoderms. The organisms represented, sometimes more than one per panel, with rare repetitions, are very numerous and the large drawings are done in tempera on a cardboard cut out and glued to the album sheets. The drawings tend to reproduce the original dimensions of the species for which the sheets have in many cases been folded several times on themselves to reduce their excessive width (up to more than 3 meters). The artistic quality is generally good, although the designers, probably more than one, have often not reported important anatomical or chromatic details, useful for a certain identification of the species. The ittionimi used are mostly Nice, often accompanied by Portuguese names, partly still valid today. Except for two figures, representing a fantasy "fish" and a non-existent monk fish, all the illustrations refer to existing species. The reasons behind the creation of this volume are not clear, from which many of the banal species of fish, molluscs and crustaceans of the north-central Mediterranean Sea are missing, while the drawings of the Nile crocodile and the Uromastice refer beyond any reasonable doubt , to specimens present in the ducal collections of living animals. The work was most likely present in the library of the Grand Gallery of Duke Carlo Emanuele I of Savoy, based on the inventory of 1659.

The volume, by an anonymous author, ranks among the most interesting and significant examples of plumarian art of the sixteenth-seventeenth-century period: the album contains eighteen anonymous figures mostly belonging to local species, grouped in sixteen plates. The birds are made up of feathers glued to a paper template applied to a silk satin background of different shades, such as to bring out the colors of the specimen's livery in the best possible way. Unfortunately, the state of conservation of most of the specimens is very precarious due to the ancient action of moths and corroding organisms that have ruined or even removed most of the feathers. The reproduction of the specimens is generally very faithful both in the shape and size of the body, and in the arrangement of the feathers and in the characteristic attitude of the animal. Unlike other contemporary compositions, where the beak and limbs are the original parts treated adequately to be able to apply them on the sheet without excessive thickness, the birds depicted in this volume have limbs, beak and eyes painted in tempera. The current arrangement of the birds on an eighteenth-century silk satin background suggests that the album was reassembled and restored after 1766 and re-bound, probably reusing the old dark red Moroccan binding with the ducal coat of arms. The work was most likely present in the Grand Gallery library of Duke Carlo Emanuele I on the basis of the inventory of 1659.

The album is a collection of fifty-two drawings, probably set up at the beginning of the seventeenth century. The tables are characterized by considerable heterogeneity in terms of scientific accuracy and quality of the stroke and are attributable to different designers: generally each table shows the image of a single plant and there are rare repetitions of the same subject; the designs tend to reproduce the original size of the species and are therefore often large. The tables can be collected in three groups related to different execution times. The first group, older, brings together small drawings, precise but of modest pictorial quality, which represent whole plants, such as cyclamen or two small ferns. The drawings are made on a cardboard cut out from time to time of different sizes, depending on the subject, and then glued to the album sheets. The second group represents many bulbous plants, particularly appreciated by collectors of the time, such as wild narcissus or in cultivated varieties, asphodels, lily of the valley, martagon lily, St. John's lily and some species of orchids. In these tables the species are almost always represented on blue paper, with great attention to the shape of the leaves and flowers but also of the underground organs, with a remarkable scientific precision for the period. The third group contains drawings of large size and of considerable artistic and scientific value which mainly depict exotic plants, such as sunflowers, Fritillaria imperialis or Canna indica or native species of ornamental or medicinal interest - the castor bean for example -, which were repeatedly represented in Painted herbs of the time as in that of the Bolognese naturalist Ulisse Aldrovandi. The work was most likely present in the Grand Gallery of Carlo Emanuele I, based on the Torrini Inventory (1659).