The semi-fluid glass is first blown out into a very large thin bulb and the blowpipe swung from side to side until the bulb elongates into a cylinder. The rounded ends of the cylinder are cracked off by applying a red-hot iron wire, and, with a straight wire, a longitudinal crack is made from one end of the cylinder to the other. The cylinder is placed on a flat stove in an annealing kiln for a few moments, when it softens and opens at the crack, gradually flattening out into a thin sheet. The circles are made by touching the thin sheet with a hot iron wire bent in the form of a circle, and the squares are cut out by applying hot, straight wires.