Industry-specific terminology can be confusing, especially for all the glassworking techniques. Our team at Daedalian Glass Studios are all experts in the glass industry but we do not expect our clients to understand the specific terms for every idiosyncrasy of our production process. However, it is very interesting (I promise) and we have created a little guide for you to understand the basic terms for glass working techniques.
A guide to glassworking terminology
Glassworking can be split into three broad categories; hot glass, warm glass, and cold glass working:
- Hot Glass is glass created in a furnace by heating glass with an open flame to over 1000°C. This glass is then usually transformed into a molten glass bubble using a blow pipe and manipulated into shape to create the blown glass sculptures, chandeliers, and other decorative items that we are all familiar with.
- Warm Glass (or Kiln Glass) is glass that is formed by heating in a kiln to temperatures ranging between roughly 600 – 900°C. Although referred to as ‘warm glass’ it is definitely still exceedingly warm! Across the temperature range, various glass working techniques can be achieved as the glass goes through a range of transformations in state.
- At the lower end (around 600°C) glass will begin to bend under the wight of gravity. This is how slumped glass is created.
- Increasing the temperature to around 700°C, glass panels start to melt around the edge but the central area remains solid. This is how tack fused glass is created – where the edges of multiple pieces of glass are fused together but their individual structures remain the same.
- At around 760 – 820°C, the entire panels of glass start to become fluid. It is at these temperatures that we create full fused glass and kiln formed glass.
- Finally, by increasing the temperature to a range between 820 and 1000°C, glass panels reach a state of fluidity where and air trapped between the panels will rise to the surface and the individual pieces of glass within the kiln will shift to the point where they become one single panel (no piece can be distinguished from the next within the panel). This is then called cast glass.
- Cold Glass is glass that is worked on to apply a decorative finish but without the glass reaching a temperature where the structure of the glass is changed in any form. Like warm glass, this term is a little deceiving as some glassworking processes commonly referred to as ‘cold’ (such as painted glass and silver stained glass) still require placing in a kiln to anneal temperatures ranging between 500 – 700°C.
- Painted glass involves painting a design in reverse onto the rear face of a glass panel – so it is then viewed through the glass. Similarly, silver stained glass involves painting a silver compound onto glass (that turns a yellow colour once fired in a kiln). As both these glassworking techniques involve the use of a kiln once the design has been applied, they are considered warm glassworking by some.
- Laminated glass is another that is not strictly cold. To create EVA laminated glass, decorative interlayers and the bonding agent have been placed between glass panels in a cold environment, it is then heated to around 150°C in a lamination kiln to activate the bonding agent. Cold-pour laminated glass, however, is created in a completely cold environment and involves the use of a two-part bonding agent that is activated when mixed together and sets over time.
- Etched Glass is a process of creating decorative patterns in abrasions on the surface of glass panels. Sandblasted glass (using a hose to project fine, abrasive grit at the surface of glass panels) is the most common form of etched glass but it can all refer to hand-drilled glass (drilling into the surface of glass), acid-etched glass (a rarely used technique these days due to the toxic waste it produces), and glue-chipped glass (applying glue to the surface of a glass panel that will chip the glass as it dries and leave a fern-like pattern behind).
- Stained glass / leaded lights are the traditional glass panels found commonly in cathedrals, churches, and old country houses. They are created by piecing together multiple smaller panels within a lead came framework.
- Brilliant cut glass is glass that is been worked using a lathe to create a diamond-like cut into its surface. Similarly, beveled glass is cut around sides to create chamfered edges. This can be done on a lathe but these days panels are usually just placed into a beveling machine.
- Finally, silvered glass (mirrors) and gilded glass are created by coating the back-face of a glass panel in metal leaf using gelatin adhesive. Verre églomisé is a variation of this which combines decorative glass working designs (usually painted glass but could also have etched, brilliant cut, or silver stained elements) with a backing of silvered or gilded glass.
Examples of how these glassworking techniques are applied in our unique luxury glass designs
Stancliffe Hall, Derbyshire
This project combined a sandblasted glass panel with cast glass design details that were bonded to the sandblasted panel using cold-pour lamination. Click here to learn about this project in more detail.
Belgravia Private Dining Room, The Lanesborough Hotel
To create these column capitals, the individual pieces were beveled and a brilliant cut design was added to the back face of the panel. This was then finished by silvering the back face before being assembled by screwing each panel together (to meet safety regulations). Click here to learn about this project in more detail.
Royal Palace, Riyadh, Saudi Arabia
This Majlis wall was created from over 1200 individual glass pieces. To manufacture, the cut glass was slumped into shape and sandblasted with a design before being silvered of the rear face. Click here to learn about this project in more detail.
As these examples demonstrate, Daedalian Glass Studios specialise in the combination of multiple glassworking techniques to create truly unique, luxury glass installations. If you wish to discuss a glass design project, please contact our team via email (firstname.lastname@example.org) or phone (01253 702 531).