Stained glass is generally misused as a term for all types of coloured windows and lead lights. More specifically, stained glass is glass which has had pigmented ‘silver stain’ painted onto its surface. This is then fired in a kiln. Once cooled, the glass is cleaned to reveal the final coloured stain beneath. When cooled the piece is washed removing the stain residue and revealing the stained glass. Hence the term ‘stained glass’ (staining of glass). Stain can range from a light lemon yellow to a deep amber depending on application and firing time. The range of stain depth variations is determined by the firing temperature of the stained glass, its actual colour, and the amount of stain applied to the unfired glass.
Many traditional windows are made out of glass which is bought as coloured sheets and then cut to the required shapes and sizes. Traditionally any detail, such as the face of a saint, is then painted on.
Whereas lead lights use the glass and lead pattern to create the design glass painting gives the freedom of working outside the confines of the lead to create detail and expression. For example the lead and glass can give the outline shape of a head whilst glass paint adds the detail and tone to give the head its features and definition. Like any paint it can also be used expressively as well as figuratively(see the work of John Piper/Patrick Reyntiens). To add detail and build up tone the glass can be painted and fired several times.
Fusible glass has been developed so that glasses of different colours can be ‘fused’ together during firing to create infinite patterns and effects. So long as all the glass you are going to fuse is compatible then you should have no problem. Glass that is incompatible may look as if it has fused but sooner or later will fracture.
These are panels and/or windows that generally only use glass – either clear or coloured – and lead, to make up the pattern.
This technique is good for adding different effects to glass. On clear glass it creates a frosted effect, whereas on flashed glass(glass which has a thin coloured layer ‘flashed’ onto a clear or coloured glass layer below it) it can allow the colour to be graduated from say a deep blue through all the tones to the clear beneath it.