Mouth-Blown Glass

Glassblowing techniques

How exactly are the hand/mouth-blown lampshades of The Blue Art Barn Lighting made? First of all, glass is made of sand, soda and limestone. These three ingredients and any other additions are mixed inside the oven at 2300 ºC. This creates thick, liquid glass. When the liquid glass has a temperature of 1130 ºC, the glass is taken out of its bowl with a steel pipe. Glass lampshades are created with a mould made of pear wood. There is a huge range of different moulds, which is evident from the large collection of lamps that is offered by The Blue Art Barn Lighting. The glass that hangs from the glass blower’s blowpipe is shaped inside the mould. Via the pipe, air is blown into the liquid glass so it will grow. By turning the glass around and around, the glass will take on the shape of the mould. Then, the glass lampshade will be broken off the blowpipe, after which the object will slowly be cooled in an oven for approximately 24 hours so that the inner tension in the glass is released. Finally, the neck is sawed off at the right height and it is polished so the lampshade is ready to be used. This final process applies to the round, ‘closed’, glass lampshades such as the Menhir and the Deco Pointy.

Glass pressing/blowing technique

The models with a more square shape are made using a slightly different technique. This process uses cast iron, pressing moulds rather than pear wood moulds. These type of moulds require two people: the glassblower and the presser. The latter holds the two parts of the mould pressed together so the glassblower can blow the glass into its desired shape. This process applies to the square, glass lampshades such as the Cube and Round-about.

Coloured glass

Various glass lampshades can be ordered in various colours. The basis of the glass lampshade is always made of transparent glass so as much light as possible can shine through the lampshade. The glass’ colour, for instance, opal white, yellow, blue, green, red or black is added after a thin, in-between layer of opaline. To create a marble effect, small pieces of coloured glass are strewn all over the hot glass lampshade at random so it melts together and the typical marble structure becomes visible. Besides the colours, the various other options are also possible. You can, for instance, choose between matte opal white glass or matte yellow glass. This effect is created by placing the lampshade in an acidic bath or by sandblasting the lampshade. Finally, there are also lamps available with a nacre shine to them. A good example of this is the lamp Sphere-Cluster.

Handmade product

Since the lampshades are made by hand and are mouth-blown, small ‘irregularties’, such as air bubbles, could be found in the glass. This side-effect is part of the natural process of glassblowing and it turns the lampshade into a unique and traditionally-made product.