In the Mediterranean region, glass was traditionally made from a slightly different kind of metal than the one commonly used north of the Alps. Instead of potash, soda was used as a raw material in soda glass, and it made the glass easy to form into very thin-walled objects. Since the Middle Ages the Venetians, who called soda glass cristallo, have been preparing exquisite and expensive soda glass vessels known all over Europe. Soda glass was typically very clear and almost colourless in appearance.
