Five Things You Didn't Know About Glass

1. Glass melts at 1200 degrees Celsius. This means that it would be impossible to use dyes as they would burn off. The colours come from metal salts. Blues - copper based. Yellow - sulphur based. Green - a combination of copper and sulphur. The most expensive are pink, orange and red - these contain 24 carat gold.

2. I think the best glass comes from Italy. But that will offend the Czechs, Austrians, Swedes and New Zealanders, who also produce high quality glass.

3. Glass is a very ancient medium. The oldest piece of glass that has been found is over 4,000 years old from Iraq and is on display in the British Museum.

4. It is impossible to mix the two types of glass - soft glass and pyrex. They have different coefficients of expansion (the amount that glass contracts when it cools). Mixing these two types of glass would lead to them shattering.

5. Lampworking is different to glass blowing. Lampworking produces solid beads and the end product is produced by layering the glass. With glass blowing the end product is hollow.