Glass fusing is the joining together of pieces of glass at high temperature, usually in a kiln. This is usually done roughly between 700 °C (1,292 °F) and 820 °C (1,510 °F), and can range from tack fusing at lower temperatures, in which separate pieces of glass stick together but still retain their individual shapes, to full fusing at higher ones, in which separate pieces merge smoothly into one another.