Abstract: A process of fabricating an inflatable item includes providing first and second three-dimensional molds, and placing first and second flexible polymer sheets over respective ones of the first and second molds. The polymer sheets are heated until the sheets conformally coat the respective molds. The heated polymer sheets are cooled such that the sheets retain the three-dimensional shapes of the respective molds. Peripheral edges of the first polymer sheet and the second polymer sheet are welded to each other to form a sealed flexible shell having an interior space that can be filled with fluid to inflate the shell such that the shell forms a three-dimensional shape. The sheets may be welded by placing the cooled polymer sheets on respective plates of a welding machine, and moving the plates toward each other until the peripheral edges of the cooled polymer sheets touch each other.