Borosilicate glass

Abacus, glass beads by Jessica Landau

Lampworking or torchworking uses a controlled torch or flame to melt the glass as apposed to a furnace as is commonly used in blown glass. In lampworking glass there are many different kinds of glass that can be used, however the most common are soda-lime glass (soft glass) and borosilicate glass (hard glass). Though soft glass is wonderful for beads and small scale projects it does however have a brittler nature than borosilicate glass and therefor has a larger propensity to crack.

Shell pendants, by Jessica Landau

Mustache goblets by Jessica Landau

Borosilicate glass is made up of a silica and boron oxide being the main glass-forming constituents. It was first developed by a German glass maker Otto Schott in the late 19th century. Borosilicate glass is good for lamp working because it has a very low coefficient of thermal expansion, meaning it does very well with heating, reheating and cooling, and doesn't have the same propensity to crack as many other kinds of glass. The glass was originally sold under the brand name "Duran," but is most commonly know by the brand name "Pyrex" which was first introduced by Corning Glass Works in 1915.

Borosilicate glass is colorless, however Paul Trautman brought colored borosilicate  widely into the market, for the studio glass trade in 1986 with the founding of his company Northstar Glassworks. until this time though borosilicate was used in the studio trade , it was still predominately a functional glass, used mostly for lab equipment and cookware.



If you'd like more information on Jessica Landau, the Artist featured in these photos her website is:  http://www.jessicalandau.com    and her online shop is:  http://www.etsy.com/shop/JessicaLandau