Amphoriskos (small amphora) made of transparent blown glass. The handles have been made separately of dark blue glass and attached later to the vessel. This type of vessel first appears in the 1st c. AD and continues until the 4th c. AD. The invention of the glass blowing technique revolutionized glass industry, reduced production costs and made glass objects available to wider social strata. The technique has not really changed until today. The glassmaker used a heated metallic tube (the blowpipe) on which he rolled a mass of glass. He blew the glass into a bubble, which he could shape in various shapes, always rotating the glass. Then, he used a rod to detach the blowpipe. He formed the details of the vessel (e.g. the rim) and attached separately made elements (e.g. handles). Finally, the rod was removed and the glass was left to cool out. As, however, the surface of the glass cools faster than the interior, there is always the danger of cracks and breakage during this stage. In order to eliminate these results, the cooling of the glass took place into special kilns, known as "annealing ovens", where temperature could be controlled.