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Outside the Mold

This paper follows up a study completed as part of the course “Research Workshop”, supervised by Dr. Tal Frenkel Alroy and Dafna Kaffeman.


Glass blowing is an ancient craft that has persisted through the ages. Glass blowers today still use tools that resemble traditional tools, and they employ techniques that are based on ancient principles, but the approach to the craft and the possibilities of design have changed and evolved to a great extent. In this paper, I shall discuss the blowing mold as an instrument that serves as a mirror for the most fundamental changes that occurred in the world of glass. Moreover, I shall try to relate the novel developments of the blowing mold with the dynamic distribution of labor between the designer and the glass blower.

Ennion, cup, mid-1st century A.D., transparent blue glass, mold-blown, courtesy of Corning Museum of Glass

The technique of glass blowing developed in the first century B.C., and about a century later, craftsmen started to blow glass into molds (Grossman, 2002). Before that, glass processing was done by hand, including chiseling and carving as in the processing of stone and wood, and the invention of mold blowing revolutionized the glass world. The mold enabled the craftsman to create many vessels, quickly and using less material, and thus it led to a significant saving in production costs (Gudenrath, 2015)11 The glass works by ... In fact, thanks to glass blowing, glass vessels became widespread and widely available (Cable, 1998) 22 In antiquity, glass ...

During the 19th century, glass blowing had its heyday. The demand for glassware increased and many blowing workshops were founded or expanded to keep up with demand. The trend culminated in the middle of that century, when in the U.S., huge factories employing about five thousand skilled glass blowers were operating in full force (Illinois, 1983). The industrial age saw, in fact, a redistribution of roles. If, up to that period, the blower was also responsible for glassware design, like in Murano, Italy, in the U.S. factories the blowers and mold designers worked in separate departments and sometimes even external designers were hired (von Wittenau, 2009).33 In 1905, François ... The glassware and molds were created by the designers while the blowers worked at the workshop; their work demanded great skill but it lacked an aspect of creativity and innovation.

Significant changes and innovations began to be introduced into the field more frequently only in the 20th century, and they resulted from the division of labor between the designer and the blower, and from new cooperative projects that enabled the designers to approach the material and the practice of glass making (von Wittenau, 2009). This move was led by Harvey Littleton and his partners at his glass studio in the 1960s. Littleton opposed the idea that glass should be blown for functional purposes only, and created artworks from the material and even opened the first home studio for glass blowing. His works challenged the conventions regarding glass working and the division of labor consolidated in the factories. An important milestone in the processes that he promoted was the introduction of glass blowing to the academy, thereby breaking up the dependence of skilled work on factories and workshops (Byrd, 2011).

Harvey K. Littleton, vessel, 1965, courtesy of Corning Museum of Glass

Even today, academies are still an important hotbed of innovation in glass blowing. Many developments result from rethinking molds, and the creation of new molds constitutes a bridge of cooperation between the designer and the craftsman. A good example for this is the academic product design project, “Heart of Glass” (2012-2014), created as part of the ECAL’s Mater Product Design program. In this project, students were asked to invent blowing tools and to use them to create a series of glass objects. During the course, they experimented with several subjects: blowing molds, work tools and new techniques. They familiarized themselves with the material’s properties with the help of professional craftsmen – not in order to specialize in it, but rather to study the effect of the material’s limitations and potential on the design process. The project was presented at the end of the Milan Design Week, as a computerized research library that includes a detailed documentation of every work, reflecting the desire to disseminate the accumulated knowledge to as many creators as possible, and to enable the continued development of research as well as to influence future creations. Although many of the tools presented in the project were not “hermetically” designed, or the products of their blowing were unexpected and not fully reproducible, the project revealed a wide variety of novel possibilities of glass blowing. This study of the flexibility of the mold has the potential to continue the evolution of the forms and techniques identified with glass, and more than that – to produce a richer encounter between the craftsman and the designer.

Harvey K. Littleton, vessel, 1965, courtesy of Corning Museum of Glass

There are quite a few works that indicate that this line of thinking has been gaining currency among contemporary creators. An example of a sponsored project of studying molds is “Breaking the Mold” (2011-2015), which took place in the island of Murano and was initiated by the CNR Office for science and entrepreneurship. The goal of this cooperation was to continue the development and reinvention of the glass craft. For this project, glass artists cooperated with designers and materials experts, who together designed and reexamined the reaction of blown glass into molds made of novel materials. The project’s website includes, among other things, a documentation of a research into molds made of fireproof fabrics. The glass adopted, in each experiment, some of the fabric-mold’s properties, for example replicating the fiber texture or spreading around threads or surfaces. Moreover, the mold itself was affected by the glass during the blowing process, as it stretched in response to the heat and the material’s mass, creating different results in each trial.

BTM team, project Pattern, 2013, blowing into fire-proof fabric molds, courtesy of Berrone Riccardo

A further example of innovative development by simpler means (and for a more modest budget) is the work of Phil Vinson (2011). Vinson builds unique molds from iron scraps that he collects and especially from metal chains, machine cogwheels and meshes. The molds he creates have moving elements and the tube’s entry point is unconventional, so that different results are obtained when the mold is moved during blowing.

The mold’s dynamics are reflected in several developments of disposable molds. One of the most fascinating cooperative projects, as part of Glasslab (2011), is the one by designer Tomoko Azumi, who developed a special technique of using cardboard-made molds that burn during the blowing stage. This technique raises some interesting questions regarding the limitations of the materials used for mold building. Here, the advantages of using disposable molds are evident, such as the ability to keep working on the product after the cardboard is consumed and the fact that no mold marks are left on the finished product.

Azumi Tomoko, from the project Glasslab, 2011, blowing into carton molds, courtesy of Corning Museum of Glass

The “Ice and Glass” series by designer Steven Haulenbeek was created in cooperation with craftsmen from a glass-blowing workshop in France, as part of a cultural exchange, and it was based on blowing into ice-carved molds (Haulenbeek, 2016). During his stay at the workshop, Haulenbeek studied the encounter of frozen water with hot glass, and he developed a technique in which single-use ice molds are used. He carved the molds in the ice and blew the hot glass into them. He also created a decorative element of cracks that formed as the water and ice touched the surfaces of the blown objects.

Another area of mold design and blowing innovation is the result of advancement in three-dimensional printing. Jonathan Keep, a ceramics designer and one of the developers of the ceramic 3D printer, turned printed ceramics to disposable glass molds (Keep, 2016). These molds can replicate computer-designed forms with precision and efficiency. He calls this technique “Ghost Pieces”, since the glass represents the shape of the ceramic mold that vanished; the transparent glass presents the ceramic vessel’s internal space, its hidden shape.

CIVA & Steven Haulenbeek, Frost, 2016, blow into snow mold, courtesy of CIAV- Centre International d’Art Verrier de Meisentha

Examining the development of blowing molds reveals to us the changes in their essence and functioning. Disposable forms, degradable materials and flux are negative elements in mold design, as far as factories are concerned. Therefore, when designers start creating in this way, they subvert the principles and logic of industrialization and the ideology that gave rise to the mold in the first place. The industrial molds, as they have become more precise, they also have become more detached from the spirit of manual production. The new molds are another expression of current trends associated with “makers” and “new craft” people, who wish to reposition the crafts person at the center of the production process. The new mold enables the designers to explore glass but also their own role as creators; it forms a bridge between the designers who wish to be in control of their work and the smiths who perform the actual work; the unknown appearance of the final product creates a balance between the two. The new molds are a symbolic part of the paradigm shift regarding the dichotomic distribution of roles , and it allows new developments that provide a source of inspiration for creation – both in the factory and in the private studio.

Jonathan Keep, Ghost Pieces, 2016, courtesy of the artist



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1. The glass works by Ennion are an example of mold blowing in antiquity. The artist’s signature appeared on his works and they became widespread all over and outside the Roman empire. The works feature beautiful, delicate decorations, mostly inspired by ceramic ware. The vessels were blown into molds that consisted of at least three parts. The large vases were blown into two different molds (one for the body and the other for the stand) joined together, while the handles were added in free forming. The molds were expertly designed to hide almost completely the seam lines. They were built from earthenware, and in order to make them, potters and blowers had to cooperate. Every mold could be used for blowing about 150 vessels, on average, before they had to be disposed. Ennion’s existence was deduced only from the signatures on the found glassware, yet it is not known where his workshop was located (and whether there was more than one), and it is unknown whether he was the blower, the mold builder or the business owner.
2. In antiquity, glass manufacturing required the melting together of a mixture of silica, sodium carbonate and calcium oxide – at a very high temperature (about 1200 degrees centigrade). To reach the required temperature, a large quantity of wood had to be burned and blown at, and then glass would be created. The time-intensive labor and the materials required for the process were the reason glassware was so expensive, even for small vessels
3. In 1905, François Coty, an owner of a glassworks factory, was impressed by the jewelry collection of René Lalique, and invited him to work for the factory. Subsequently, Lalique became an expert on glass and glass molds.


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