A combination of various elements are needed to manufacture glass. Soda ash, lime and sand are the key elements used to manufacture glass; a particular mixture of these elements is heated at extreme temperatures until it melts down. The respective mixture then goes through a blowing and pressing process to become a glass we know. Ultimately, the glass will go through an annealing process (a reheating and cooling process). In fact, this process is the one that distinguishes standard glass from tempered glass.