Green teas are produced in virtually every growing region and come in an amazing variety of forms. Processing may begin with withering (air drying) but this is not required. Fermentation is prevented by heating immediately after withering. Here one of the first variations occurs. Heating may be by steaming, hot air treatment, or pan firing. The desired result in any method is that the leaves retain their green color as much as possible. Then the leaves are rolled, either manually or by machine. Small leaves may be rolled lengthwise (Precious Eyebrows), or into pellets (gunpowder). Larger leaves may be curled or rolled into pearls. Japanese pan fired teas are left flat. Then the leaves are dried, in hot-air driers or by being spread out under the sun, to complete the processing.