By: Alexandra Anith Střelcová
Photo: Shotby.us
Glass fusing is a meticulous process that demands both precision and unbridled creativity. A release agent, a refractory material resembling fine sand, is evenly sprinkled on the base surface. Once the layer, at least two centimetres high, is perfectly smoothed, desired textures are shaped using a variety of distinct – and often unorthodox – tools. The final pattern will be imprinted on the flat sheet glass once it’s heated in a special kiln
An array of tools and techniques are deployed in order to closely match architects’ visions. “Usually we might use spoons, brushes, rollers adorned with motifs, or bubble wraps – and even our own hands,” explains Šárka, who has been working in Lasvit’s glass works for two years now. Once the texture is ready, glass is positioned onto the surface, then heated to high temperatures until it melts, fusing all the pieces together
Purposefully layered additions disrupt the initial geometric framework, resulting in a unique relief. “Every time the procedure unfolds, we gasp with anticipation as to the outcome,” reveals Šárka. The release agent’s inherent stickiness requires extremely thoughtful movements marked by minute attention to detail. A single chance, any failure means a start from scratch, having to prepare the entire surface again.
Opting for a roller with a printed pattern or a textured surface may yield a refined structure upon imprinting, attaining the sought-after effect. “The release agent’s key advantage lies in its post-firing properties–it levels out and can be easily scraped. Or we can add a fresh layer, paving the way for subsequent iterations,” notes Šárka. It stands as a versatile material, amenable to multiple uses
Bespoke designs require bespoke moulds – and these need to fit with millimeter precision. “We pride ourselves on working with the smallest tolerances. Sometimes, things get tricky as molten glass is a living material,” says Šárka. To facilitate separation, moulds are coated with a substance that prevents the glass from sticking. During the tempering process, lass gently fuses into the desired shape
What if fused glass could stand as a testament to the intricate beauty of nature itself? Firstly, plants are laid on a heat-resistant phase paper. Woody stems like thuja, pine or spruce work best, as delicate ones may burn in the process. Under high temperatures, plants leave their imprint in the glass, creating a sophisticated decor. The outcome is always a surprise, adds Šárka. “We play with the glass, and the glass plays with us."
An array of techniques is employed to achieve a distinctive texture. Utilizing frit, crushed glass particles, housed within heat-resistant frames made of vermiculite contributes to the process. As the flat glass is positioned within the form, the tiny shards are imprinted during the temperature process. In the fusing process, elements such as sprinkled frit create a delicate crumb effect that gleams beautifully when illuminated
Aside from frit, some rather unexpected materials are often employed in the process. Typically found in a gardening store, perlite or expanded clay is repurposed here to enhance the aesthetics of the final design. Alongside vermiculite, another mineral with similar uses, the volcanic popcorn is valued for its ability to withstand scorching heat and kiln fire. Moreover, it contributes to the creation of uniquely intriguing patterns
Before the actual glass fusing begins, each mould must be coated with a separation agent in a process not dissimilar to greasing a cake mould before baking a delicious treat. Here, the special substance is used to prevent the glass from sticking, safeguarding the moulds from damage. Coating and firing are also required before the moulds’ first use. Only then can the glass be placed on the material, and the production process begins.
Phase paper is a special refractory material that possesses a host of useful characteristics and serves diverse purposes in fused glass production. Despite its specialized nature, it can be torn, cut, or shaped with bare hands. “The material offers versatility, allowing for different approaches to creating textured impressions in glass,”explains Šárka. Here is a ready-to-use mould, with the phase paper affixed to a thicker base.
Phase paper can also be soaked in water and moulded manually into the desired form. Glass is then placed on it, and the texture produces a unique undulating surface. Strips cut from phase paper can be spaced in various areas, depending on the subtlety of the decor, resulting in a geometrically regular pattern. “The magic of fused glass lies in its countless renditions,” says Šárka. Here is the final element, once it has cooled.
Historically, fused glass emerged from a process of experimentation and continuous innovation, reflecting human creativity and inventiveness. For Šárka, the technique undergoes constant perfecting in Lasvit’s glassworks. “The Czech people have a particular penchant for playfulness,” she concludes. Indeed, it’s a never-ending journey that transforms ordinary sheets of glass into a captivating spectacle fused with a powerful story