Abstract: The invention relates to a forming screen for use in the forming section of a paper machine, comprising a paper and a machine side as well as longitudinal threads extending in the intended running direction and binding cross threads extending transversely thereto, wherein the longitudinal threads are divided in the ratio of the number of threads of 1:1 in a longitudinal thread layer on the machine side and a longitudinal thread layer on the paper side, and the binding cross threads bind in both longitudinal thread layers, which is characterized in that the forming screen has a fiber support index (FSI) which is in the range of 230 to 250 and has an air permeability which is in the range of 5700 to 10600 m3/m2/h.