Decorating glass whilst it is still molten is as old as glass itself. It took various forms, ranging from adding dabs of glass and pinching them for decoration, or trailing different coloured glass in bands to dipping the glass into moulds. These techniques were employed for centuries in much the same vain. The Venetians took some of these techniques to high levels with their Façon de Venise glasses. With the invention of lead crystal glass, in England, by George Ravenscroft in the mid 17th century, applied prunts and pinched bands became a characteristic of his glass. However, this type of decoration did not evolve until John Northwood, the man normally associated with the Portland Vase and the reinvention of cameo carving on glass, took it to a new artistic level. He invented equipment and tools to help the worker to create styles that are synonymous with Stevens & Williams.
For centuries colourless flint glass was used for the finer table glass with the less refined green or brown glass being employed for the more utilitarian bottle or domestic glass. Colour is added to glass by the incorporation of different minerals and young designers like Frederic Carder exploited this technology to introduced a wide pallet of colours. Some colours change during the manufacture and are referred to as heat sensitive glass. Other coloured effects were created by casing one or more layers of different coloured glass on top of each other.
Adding threads or trails of coloured glass onto the body of a vessel was made easy by the invention of equipment to aid the worker to place it accurately on the vessel. A further invention by John Northwood enabled these threads to be pulled and manipulated in an artistic manner.
Another invention, this time by Thomas Wilkes Webb, covered an improved method for the exposing of molten glass to the vapours or fumes arising from the evaporation of tin or other metallic salts when acted upon by hydrochloric acid. The effect was to produce iridescent colours on the surface of the glass.
All of these techniques were copied by numerous less capable manufacturers and hence result in too many false attributions for Stourbridge glass. In the members area, we will examine each of these in turn so that a more appropriate judgement can be made when identifying Stourbridge glass.