Opaque twist Stem Wine Glasses 1755 to 1780
The opaque twist threads were first produced by the venetians making the famous techniques such as the vetro di trino and Latticino stem designs.
The opaque white rods of glass are produced by the addition of oxide of tin into the mixture to produce white rods of glass that could now be placed into a round circular mould where the introduction of clear glass would heat the white rods while the glass blower would then manipulate and twist the glass to draw out patterns of white opaque spirals, hence the invention of the opaque twist stem.
Some pattern styles are known as the cotton twist, corkscrew twist, multiple series opaque twist MSAT, lace twist, spiral gauze, lace twist outlined and spiral threads and the introduction of knops also enhanced the appearance while making the glass more unusual and the more knops the rarer the stem formation is.
Coloured Stem Wine Glasses
From 1750 the introduction of coloured rods of glass was introduced by the addition of enamels and why so few were produced remains a mystery.
Some of the colours used were Black, Red, Green, Blue, Maroon and Yellow. The rarest being blue and yellow.
Mixed Colour Twist
The mixed coloured twist refers to the combination of both air and opaque twists in the stem of the glass. Sometimes colours were also introduced making the glass quite a rarity.