I'm thinking of deleting my other blog, and will transfer some of my posts to the current one. Here's one of the posts:
A clear glass teapot set from Y.W.Y.
The material is Borosilicate glass, which contains at least 5% of boric oxide and makes them resistant to high temperature. This type of glass requires greater heat to produce and is popular for laboratory glassware.
Soda-lime glass is a cheaper material than Borosilicate to produce most kitchenware or glass bake-ware.