Mouth blown antique glass is "stained" by mixing various metal oxides into the glass while it is still molten ... cobalt for instance creates cobalt blue, gold is used to create red.
In full antique glass, these metal oxides are added by hand from secret formulas or at the whim of the glassblower, creating a unique hue never to be duplicated.
Mouth blown glass is the traditional way to produce glass. The success of this old technique relies on the skill of a master glassblower.
Once the silica sand and metal oxide is heated in the furnace, the glassblower gathers a molten mass and blows it into a large cylindrical shape. The ends are cut off this cylinder and it is cut along its length so that the cylinder can be opened out into a flat sheet using sticks. These sticks (kreuckels) create markings (striations) in the glass surface. The intense colours and striations and “seeds” (air bubbles trapped in the molten glass) are what give antique glass its beautiful, vibrant character.
Because the entire process is done by hand, each piece is unique and the thickness of the glass varies.
Drawn antique is "pulled" vertically by machine from the furnace and passed through rollers to make it into sheets. This glass has similar striations to full antique glass and has consistency of colour and thickness as these processes are done by machine.
Flashed glass is mouth blown glass that has at least two colours on one sheet. A thin layer of different colour(s) is “flashed” onto the surface during the glass blowing process. This glass is used for acid etching or sandblasting. The piece is "masked", leaving a portion of the design exposed. The acid is then applied, which dissolves the flash, exposing the underlying colour.
designs/images © Kathie Lloyd 1997-2009