Film webs are joined together and yarns are sewn into the films in the screen length and width directions to form a network on at least one side. The yarn network and films are heat-set. A screen for use inside a greenhouse is designed to be positioned horizontally in order to form a layer of air underneath the roof which has a different temperature than the air in the rest of the greenhouse, in order to prevent condensation dripping from the roof. The screen comprises film webs which are joined together along their edges or are overlapping. Yarns are sewn into the webs in the length and width directions of the screen to form a network on at least one side of the film. The thread network and films are heat-set so that they are dimensionally-stable.
