In the context of this artwork, explain the Analysis of the Support for Leonardo attribution.
In 2010, after a two-year study of the picture, Kemp published his findings and conclusions in a book, La Bella Principessa: The Story of the New Masterpiece by Leonardo da Vinci. Kemp describes the work as "a portrait of a young lady on the cusp of maturity [which] shows her with the fashionable costume and hairstyle of a Milanese court lady in the 1490s". By process of elimination involving the inner group of young Sforza women, Kemp suggested that she is probably Bianca Sforza, the illegitimate (but later legitimized) daughter of Ludovico Sforza ("Il Moro"), duke of Milan. In 1496, when Bianca was no more than 14, she married Galeazzo Sanseverino, captain of the duke's Milanese forces and a patron of Leonardo. Bianca was dead within months of her marriage, having suffered from a stomach complaint (possibly an ectopic pregnancy). Kemp pointed out that Milanese ladies were often the dedicatees of volumes of poetry on vellum, and that such a portrait of a "beloved lady" would have made a suitable title page or main illustration for a set of verses produced on the occasion of her marriage or death.The physical and scientific evidence from multispectral analysis and study of the painting, as described by Kemp in the first edition of his book with Cotte, may be summarized as follows:The technique of the portrait is black, red and white chalks (trois crayons, a French medium), with pen and ink.
The drawing and hatching was carried out entirely by a left-handed artist, as Leonardo is known to have been, although restorations are by a right-hander.
There are significant pentimenti.
The portrait is characterized by particularly subtle details, such as the relief of the ear hinted at below the hair, and the amber of the sitter's iris.
There are strong stylistic parallels with the Windsor silverpoint drawing of A Woman in Profile, which, like other head studies by Leonardo, features comparable delicate pentimenti to the profile.
The members of the Sforza family were always portrayed in profile, whereas Ludovico's mistresses were not.
The proportions of the head and face reflect the rules that Leonardo articulated in his notebooks.
The interlace or knotwork ornament in the costume and caul corresponds to patterns that Leonardo explored in other works and in the logo designs for his Academy.
The portrait was executed on vellum—used by him in his illustrations for Luca Pacioli's De divina proportione (1498). We know from his writings that he was interested in the French technique of dry colouring on parchment (vellum). He specifically noted that he should ask the French artist, Jean Perréal, who was in Milan in 1494 and perhaps on other occasions, about the method of colouring in dry chalks.
The format of the vellum support is that of a √2 rectangle, a format used for several of his portraits.
The vellum sheet was cut from a codex, probably a volume of poetry of the kind presented to mark major events in the Sforza women's lives.
The vellum includes a palmprint in the chalk pigment on the neck of the sitter, which is characteristic of Leonardo's technique.
The green of the sitter's costume was obtained with a simple diffusion of black chalk applied on top of the yellowish tone of the vellum support. (Kemp has subsequently expressed reservations about this evidence.)
The nuances of the flesh tints were also achieved by exploiting the tone of the vellum and allowing it to show through the transparent media.
There are noteworthy similarities between this work and the portrait of Cecilia Gallerani, including the handling of the eyes, the modelling of flesh tones using the palm of the hand, the intricacy of the patterns of the knotwork ornament and the treatment of the contours.
The now somewhat pale original hatching in pen and ink was retouched in ink in a later restoration, which is far less fluid, precise and rhythmic.
There have been some re-touchings over the years, most extensively in the costume and headdress, but the restoration has not affected the expression and physiognomy of the face to a significant degree, and has not seriously affected the overall impact of the portrait.
Milan vellum silverpoint title page pentimenti Ludovico Sforza codex Sforza Leonardo da Vinci hatching ectopic pregnancy right Vinci caul Cecilia Gallerani relief Windsor trois crayons interlace Jean Perréal