This type of specially produced mouth-blown sheet glass is given their tint not simply by adding colour to the batch. Their colouration is created by means of the flash technique: The clear or tinted carrier glass is over-laid with one or two layers of coloured glass thus opening almost unlimited possibilities of variation.
Consequently, multicoloured „flashes”, even curves and slight shadings as well as cloudy and „torn“ open glasses can be produced.
White milk glasses of opaque or opal quality which allow light to shine through but prevent inquisitive eyes from invading people’s privacy offer another large field of applications.
As a molten gather, the substance later to be called „flash” is first brought to the blowpipe. Here the shape is instrumental in bringing about the appearance of the flash. A round balloon produces a uniform flash, a pearshaped gather creates a shaded flash, and small notches a torn flash. The molten carrier glass is then applied over the small gather and blown into a cylinder shape. During the process of blowing, the appearance of the flash is kept under control.
After completion of the glass cylinder, the remaining stages of production are identical to those of the Clear and Coloured Glasses.
The shaping and colouring process of the flash requires deliberate control, experience and craftsmanship on the part of the glassblower.
The size of a sheet is approx. 60x90 cm (24" x 36"), its thickness is approx. 3 mm (1/8"). All the sheets are supplied with their edges intact. Small variations in the dimensions occur due to the handmade production of the individual sheets.