In particolare durante il periodo rinascimentale Firenze si distinse per l’ottima qualità della lavorazione del metallo. Un pregevole esempio di tale produzione è rappresentato da una copertina in argento che fa parte della collezione del Museo d'Arte di Cleveland. Originariamente commissionata da un cardinale francese, il pezzo risale al 1467 o 1468 circa ed aveva la funzione di abbellire l’esterno di un evangeliario   appartenente al cardinale Jean La Balou. La rilegatura è realizzata con una serie di placche in argento finemente incise tenute insieme da bordi  in argento dorato. La parte centrale del fronte di copertina raffigura scene dell'infanzia di Cristo, dell'Annunciazione, della Natività e dell'Adorazione dei Magi. I bordi della rilegatura consistono in elementi decorativi quali sfingi, ghirlande, angeli musicanti, santi. Il retro della copertina, raffigurante scene della passione e della crocifissione di Cristo, è anch’esso sopravvissuto ma appartiene alla collezione del Minneapolis Institute of Art.

A walk across the famous Ponte Vecchio in Florence reveals an abundance of glittering shops, some selling leather goods, but most are those of goldsmiths and jewelers. The current bridge was built in 1345 replacing an earlier one destroyed by floods. In 1593, Ferdinand I, Grand Duke of Tuscany, decreed that only goldsmiths and jewelers be allowed to have their shops on the bridge in order to replace the butchers and fishmongers formerly there, and thus improving the well-being of all Florentines as they walked over the bridge. Today, the spectacle of glittering gold and silver should remind us that Florence has not only been an important center for painting, sculpture and architecture. Florence was also an important city for the production of high quality metalwork, particularly during the Renaissance.

In the Cleveland Museum of Art will be found a beautiful product of that era; a silver book cover originally commissioned by a French cardinal. The cover was made about 1467-1468 to embellish the front of a gospel book belonging to Cardinal Jean La Balou (1421-1491). The binding is made up of a series of silver plaques held together by gilt-silver borders. Each plaque was individually engraved to produce a decorative image. The center of the binding depicts scenes from the infancy of Christ, those of the Annunciation, the Nativity and the Adoration of the Magi. The borders of the binding consist of various decorative elements such as sphynxes, garlands, music-making angels, saints, and, at the center of each border panel, the coat of arms of Cardinal Balou himself signifying his ownership. The back cover of the gospel book also survives but in the Minneapolis Institute of Art. The back cover depicts scenes from Christ’s passion and death on the cross. Symbolically, the two covers would represent Christ’s entry into the world and the fulfillment of his mission on earth through his death and resurrection. These were appropriate images for a Gospel book, the full text of the Gospels by the evangelists: Matthew, Mark, Luke, and John.  

More likely, the cardinal’s book was a Gospel lectionary which contained Gospel readings for the Mass, arranged according to the liturgical year. Such books were used on the altar in conjunction with the missal. Gospel lectionaries not only served as liturgical books for the clergy at the altar, but also as visible symbols of the word of God. For this reason, their bindings often received lavish decoration in the form of precious metals sometimes combined with ivories or gemstones. This made them especially visible to the faithful who could observe them on the altar or carried in procession. Inside, the book itself would no doubt have been enriched with beautiful illuminations. The special enrichment of Gospel Books and Gospel Lectionaries was a tradition of great antiquity extending back to the 7th and 8th centuries.

Cardinal Jean La Balou would certainly have understood this tradition and would have wished to project his own patronage and good taste by commissioning a Gospel Lectionary of suitable richness and elaborate decoration. It would have been used by the cardinal at the altar during Mass. The silver plaques that comprise the binding of his book are engraved in a technique that was mastered by Florentine craftsmen above all others. It is known as niello. The goldsmiths of Florence in the middle of the 15th century ornamented their works by engraving the metal with an instrument known as a “burin.” After engraving a pattern into the silver, they filled up the hollows produced by the burin with a black enamel-like compound made of silver, lead and sulphur. After firing, the resulting design, called a niello, was of much darker contrast and thus much more visible against the silver plaques. It was a technique for which Florentine goldsmiths were well-known across Europe. It would therefore be no surprise that a French cardinal would come to this city to purchase a special binding for his book.

Cardinal Jean La Balou had a complex and unfortunate history. He was born of humble parentage in Poitou. In 1461 he became vicar-general of the bishop of Angers. His cunning and mastery of intrigue earned him the appreciation of the French king, Louis XI, who made him almoner. In 1465 he became bishop of Évreux. The king made him a member of his council and obtained for him the cardinalate in 1468. Unwisely, Cardinal La Balou intrigued against his patron by conspiring with the king’s rival, Charles the Bold, Duke of Burgundy. Their secret correspondence was intercepted and, in 1469, Balou was thrown in prison, where he remained for 11 years. This, sadly, happened shortly after receiving his beautiful new Gospel Lectionary with its silver and niello binding. Perhaps in an effort to win his release from prison, Balou presented his book to Pope Paul II as a gift, though the effort appears to have failed. It was not until 1480, through the intervention of Pope Sixtus IV, that he was set at liberty. From that time, Balou lived in high favor at the papal court in Rome. He died in Ancona in 1491.

The exquisite binding from the cardinal’s Gospel Lectionary may, on the one hand, signify unbridled ambition, but it also provides us with a superb masterpiece of the Florentine art of niello. The book is known to have remained in the papal apartments until the end of the 18th century, perhaps leaving when Napoleon’s troops held the Vatican. The book, itself, is not known to have survived. However, history has thankfully left us its binding, an example of a little-known art form in Renaissance Florence.