This manufacturer in Murano invented a centrifuge machine and technique that spins molten glass into discs that are then manipulated by hand into various organic shapes. During the process varying colors and finishes are applied to the glass. Still warm pieces are put through an annealing process in a tunnel oven to cool slowly so as not to explode. The annealing process can take anywhere from hrs. to many days depending on the thickness of the glass Annealing is a process of slowly cooling glass to relieve internal stresses after it was formed. The process may be carried out in a temperature-controlled kiln known as a Lehr. Glass which has not been annealed is liable to crack or shatter when subjected to a relatively small temperature change or mechanical shock. Annealing glass is critical to its durability. If glass is not annealed, it will retain many of the thermal stresses caused by quenching and significantly decrease the overall strength of the glass.