Iconography and common knowledge usually associate glass with transparency, while the typical gleam of the material transferred to the objects defines one of its most given features, stated also in words as in glassiness.
As a practice well established in the Middle Ages – and before – painters had taken advantage of the fact that glass offers a wide range of opportunities to play with reflection, optic and viewpoints. A goblet or a ewe half-full of wine on a table, the liquid seen through the container, could be used not only to depict both a banquet and a simple meal, but it also provided an opportunity to the artist to show his ability. The latter by means of how that depiction could improve, in a richer form, the desired suspension of disbeliefs between the painting and the viewer. For that purpose, scenes of banquets (and interiors in general) became more frequently enhanced by the representation of glass items in form of tableware, vases and less common objects too, used to expound the nature of the setting or as metaphorical symbols associated to the people portrayed in the opera.
Portrait of a man by Moretto da Brescia (Alessandro Bonvicino), oil on canvas, ca. 1520-25
The Met, Metropolitan Museum of Art (New York), accession number 28.79 – Public domain
This became an even more interesting and valuable challenge during the Renaissance, with the completion of the perfection process that resulted in the birth of crystal glass around 1450. The new purer typology of transparent glass marked a passage in the history of glassmaking and its colours. Since Antiquity, chemical composition and impurities in the raw materials had always lent greenish and greyish shades to glass, that glassmakers had empirically learnt to diminish with the use of ingredients like manganese, that could made glass more transparent and colourless. With the development of the techniques used to choose and clean the raw materials and the birth of crystal glass, finally glassware reached the limpidness and shininess that before had been the trait of rock crystal. The immediate success of this new typology of glass and the circulation of crystal-ware increasingly inspired figurative arts: colour effects based on the “absence” of colour, for example vases or jugs with water within, became common elements in paintings and possibly protagonists with the growing success of still lives.
Nonetheless the same practical tests that from the first attempts in Ancient times led to the knowledge of solutions to clean the material, also taught glassmakers to dominate its colouring. The combination of gleam and colour not being less eye catching and pleasant than transparency. Stained glass windows decorated medieval churches with a richness that could compete with frescos and were used as much as the latter to educate the worshippers and to enhance the house of God, given the broad opportunities to depict scenes using small glass panels in an infinite array of shades. The same is true for mosaics, that could also be made of small glass tiles and combined with stones. At the time the manipulation of glass derivatives such as enamel had seen a long tradition in other arts too, like in jewellery; and was spread not only in Europe but worldwide. Coloured glasses could imitate precious and semi-precious stones (famous was the quality of the ones made in Venice, the so-called veriselli), but enamels could provide a variety of palette and a pliability in the painted patterns that, thanks to their durability, elevated the opulence even of silver and gold. Enamelled jewels and objects were wanted and valued among all cultures to show wealth and elegance.
Copper ewer with painted enamel, partly gilt, partly brass - Venice late 15th-early 16th century
The Met, Metropolitan Museum of Art (New York), accession number 17.190.563 – Public domain
Jewish wedding ring made of gold and enamelled, attributed to Venice or Germany (possibly Eastern Europe), 16th or 17th century
In this context coloured glass in form of glassware continued, however, to hold and important place in Renaissance glassmaking, despite the fortune of transparent crystal glass (and the persistent success of enamels). First of all crystal glass could also come in coloured form and became fashionable since the 16th century. Above all reddish and bluish hues started to be sought-after, and as a matter of fact receipts to obtain such shades fill up coeval recipe books for glassmakers. For example, to the making of the vivid red known as “rosechier” were dedicated tens of glassmaking directions, in order to cover all its range of tones. The combination of colourful glass in one shade and metal decorative elements became very appreciated during the Renaissance too.
However the importance of colour in Venetian glassmaking had started before. Since the 15th century coloured glass became, in fact, one of the engines that favoured the success of the local manufacturing. On one hand glassmakers from Murano started to improve techniques known since the Roman era and that had already reached them by means of the Byzantine and Islamic tradition. While on the other, at the same time they invented new solutions and types of glass: initially under the influence of imported products, then giving free hand to their taste and ingenuity.
The successful appearance of Chinese porcelain into the European market of luxury goods led up to the creation of one of the most important innovation in Venetian glassmaking, that is lattimo. Lattimo glass is characterized by its white colour combined with lively shininess, in order to be used to imitate original porcelain from the Far East. Also, lattimo items were usually painted with the employ of enamels, not differently from what was typical for porcelain, thus starting to merge not only different tastes in material culture, but also making profitable use of diverse forms of the same material and its characteristic ductility. On the contrary, another coeval coloured innovation of the Muranese glass-manufacture did not need to be painted: it was calcedonio glass. This sort of dark brownish and yellowish glass reproduced the effect of the eponymous stone, so beloved at that time. This finding started a long-lasting success that after the initial growth between the 15th and 16th century, found a new revival during the 18th-19th centuries.
Painting on glass, however, was already a common trait especially in Venetian glassworks of the period. Dotted patterns in blue, red and green are recognised as a common feature in Venetian glassware from the second half of the Quattrocento till the beginning of following one, used not only on colourless glass, but also on coloured glassware. Applied to enhance hems and other simple decorations in a multitude of items, they were mixed with a widespread use of bright gold-leaf and more complex paintings, representing coats of arms, religious or mythological scenes and other motifs to honour individuals or important events, like weddings.
The Met, Metropolitan Museum of Art (New York), accession number 14.83 – Public domain
During the same decades in Murano millefiori glass (literally “thousands of flowers glass”) became popular. Originally invented during the Roman period, it was refined by Venetian masters and started to be used for a wide assortment of items. Featured by an intense blue or by a colourless background, the small colourful flowery decoration became well liked in the form of vases, bowls and other containers. With a similar technique, in Murano glassmakers started to create complex patterns from thin glass strings, to be converted into glass beads, thus beginning the long history of one of the principal glass productions in Venetian history. And despite the alternating success of the millefiori type in the field of glassware, its role in bead-making persisted during the centuries, being the ancestor of the even nowadays popular murrina glass (created in the 19th century).
On the other hand, the prevalent success of transparent glass during the 16th century is due not only to colourless glass and crystal gleam, on the contrary colours in particular in the shades of white and blue played a fundamental role in the renowned Venetian glassmaking. During the first half of the century Muranese masters were able to redefine the concept of style in glassware, thanks to a series of innovations that shifted the common taste and set new standards both in Europe and in the Near East, thus finally leading to a new model to follow and setting what will be then called “façon the Venise”. In this process the role played by white lattimo is as important as the one of crystal. Developments and new products like filigree and reticello glass could have never been created without the creativity and ingenuity of the glassmasters in merging the elegant contrast between transparency and gleaming white; between colourless shininess and white twists created by thin lattimo strings. If common glass is also usually known as “white glass”, looking at those innovations it shall instead be important to distinguish between one use or the other of the idiom, and recognize the important role played by white glass as a proper colour, in combination with colourless transparency.
The same ability in mixing clearness and a juxtaposing vibrant colour shade is true for the new trend in Venetian glassworking during the second half of the 16th century. It introduced bright dark blue details to adorn stems, grips and other decorative motifs on the objects. A taste that will find its definitive triumph in the following years and then in the 17th century, with the diffusion of ornamentations in shape of blue small animals (such as dragons and snakes) or elaborated trimmings and blue parts applied on the object. The contrast between colourlessness and blue is also the style that will definitively open the season of the façon de Venise school. The one that ultimately stated Venice as the trendsetter in Renaissance glass. A result obtained not only by means of transparent, light-catcher crystal, but also with an innovative use of colours and colourless transparency in glassmaking.