From Aachen Cathedral (805AD) until the 1980’s traditional stained glass, meaning leaded glass, remained the only practical and enduring method of creating architectural glass artworks. My first book, “Contemporary Stained Glass”, published in 1989, in both France, the UK and the US, gives a detailed overview of the artform at that time. At that time, it was a matter of pride in the ‘industry’ that nothing had essentially changed for over a thousand years, and ‘Contemporary Stained Glass’ documents the many exciting and modern artworks being created with this medieval methodology.
But, within a few years of its publication, the book was fast becoming out of date, as suddenly artists and studios sought to escape from the tyranny of lead and find ways to make much larger panels to accommodate the language of contemporary architecture, which seeks to have ever larger glass panels.
To remedy this my next book, “Architectural Glass Art” 1997, sought to bring things up to date, including a large section called ‘Transcending Lead’, which explored the many changes in technique that were just beginning.
Once change started there was no going back and so in 2006 I had to publish “Colours of Architecture” which had no leaded glass in the book at all, and focussed entirely on the many emerging techniques involving float glass, including screen-printed enamels, coloured interlayers, bonded on glass, slumped and fused glass and so on.
But life does not stand still and since 2006 much has already moved on, with digitally printed ceramics and interlayers enabling images and colours to be added to float glass in very large sizes and at ever decreasing costs.
From the artistic and aesthetic point of view all these innovations are tremendously exciting. From a manufacturing point of view they are alarming, as is all innovation, because it renders potentially redundant hard-won skills, crafts and expertise. This is the nature of change and we are definitely living in a rapidly changing world..
This technique involves mouth-blown glass, cut into shapes, perhaps painted and fired, and then held together in a mosaic of lead. The industry is permanently renewed by the need to restore and upkeep so much medieval and victorian stained glass. As a medium for modern glass art it is still relevant in older buildings but less used in contemporary buildings.
This technique involves genuine mouth-blown glass, which has a rich colour, texture and beauty unmatched by more contemporary methods, bonded to large sheets of float glass. The antique glass has to be cut accurately to create a tight mosiac. The technique enables the overall panels to be large, and creates a more fluid aesthetic without the required black outlines of lead.
These can be screen-printed, airbrushed or painted onto glass and then fired. The glass can be transparent or etched. The colours can be very rich and deep, though some specific colours cannot be achieved with these enamels. There is something mysterious and alchemical about transparent enamels – they can be unpredictable when mixed and even show subtle changes in colour depending on whether you print on the tin side of glass or not! Printing can be done one colour at a time, on one surface of a piece of glass only.
The enamelled glass is fired in the toughening plant, thus the emerging product can be of any thickness and can conform to all building regulations.
These are much more widely used commercially, the result frequently being referred to as ‘fritted glass’. The opaque enamels are more predictable than transparent enamels, and can achieve almost any colour. They show up equally from the interior or the exterior. But, they are not same as transparent colours and, in my view, can seldom match them in subtlety and beauty. See also here (Word doc. 26kb)
These are essentially the same medium but, instead of being screen-printed onto the glass one colour at a time, they pass through an ink-jet system. Thus a multicolour image can be created in a single process. After printing the enamels are fired in the normal way making them completely permanent. The process, as so often with the latest technology, is produced at much lower cost.
This process implies that something is printed using a digital printer and is then laminated inside two panels of glass. The interlayer can be the actual PVB material itself, and this method probably achieves the most permanent result, but other film products can be successfully laminated between two layers of glass with great reliability.
The advantage of digitally printed film which is bonded onto glass is that it is impermanent. This means that images can be replaced when required, which in many contexts is an essential requirement. The technique is widely used in the retail business and in office partitioning, where its impermanence and low cost is an asset.
This is a technique not widely used, but that has applications in certain contexts. Optimally the shapes are carved into glass with a sandblaster. This creates a perfect bonding surface for the resin as well as defined shapes for the colours. The colour is then poured or painted onto the surface of the glass. This resin brings the glass back to transparent, which makes the colours very striking. The colours can be very rich and can be mixed to create striking effects.
Glass is heated over a mould to a temperature that allows the glass to slowly sag into a mould. Moulds can be created from many different materials giving many different effects. The availability of computer controlled kilns, that can heat and cool glass at controlled speeds, transformed this process from something complex and time consuming to something that can almost be done at the push of a button. The range of shapes, textures is infinite. The glass can be toughened. The technique creates a glass that is very textural and organic and works very well in older buildings as well as new.
This is a process where layers of glass are heated to quite high temperatures so that they fuse together. This can be done with coloured glass, powdered colours, layers of float glass, creating different shapes etc.
Etching glass refers to both acid-etching and sand-blasting, both of which remove the transparency from glass by changing the surface. Acid etching is less used now as there are ceramic enamels which almost perfectly mimic the effect of acid etching. This means that repeated patterns can be created at very low cost, and a the effect is much more durable and scratch resistant than acid etching. Sandblasting is mainly a way of carving into glass and thus creating relief patterns.
This is just one of many different types of glass on the market. Dichroic glass has a coating which means it is sometimes transparent and sometimes reflective and each mode reveals a different colour. Mostly the glass will be somewhere between these two extremes so the glass can reveal many different mixtures of colours.
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