Abstract: A modular hot air dryer includes air jet support for a continuously moving, freshly printed flexible paper web. Air curtains are provided at the dryer entrance and exists to prevent excess fresh air penetration into the dryer. Air which is intentionally introduced is preheated before being introduced through the air curtains to help avoid tar build-up. Automatic control is provided of the exhaust flow rate to maintain constant vapor concentration. Each zone of the dryer is separately temperature-controlled.