Borosilicate glass is not like normal glass. With borosilicate glass the main constituents are silica and boron trioxide. This combination gives borosilicate glass very low coefficient of thermal expansion, this makes it resistant to thermal shock and thermal stresses. Historically borosilicate glass is commonly used to make test tubes, however with the advent of 3D Printers, it has found a new application.
An ideal 3D Printer build surface needs to be perfectly flat, and glass is a good candidate for this. However normal window glass will expand under the temperature fluctuations of a 3D Printer heated bed. If it is constrained around the edges (i.e bulldog clips) this can cause it to bow in the Z Direction and effect your print quality; even worse it will crack. Using borosilicate glass overcomes these pitfalls from using normal glass, and is the ideal solution for 3D Printer build platforms.
We can guarantee that the glass we sell is genuine borosilicate glass, many suppliers of so called borosilicate glass, are in fact supplying soda lime glass. The difference can be easily spotted, soda lime has a blue tinge around the edges, whereas borosilicate glass has a slight yellow tinge.