Abstract: The invention relates to a filter element for filtering fluids, comprising a flat support structure which forms the wall of a support tube (1) which surrounds the exterior of a filter medium and forms a through-flow surface and a marking surface (9), the through-flow surface having through-flow apertures (5) forming a perforation pattern (3) and the marking surface (9) having visibly discernible marking elements (11). The filter element is characterized in that the marking elements (11) are formed in the marking surface (9) by a second perforation pattern (13) which contrasts with the perforation pattern (3) of the through-flow surface in a visibly discernible manner.

Abstract: The invention relates to a filter element for filtering fluids, comprising a flat support structure which forms the wall of a support tube (1) which surrounds the exterior and/or interior of a filter medium and has through-flow apertures (5) forming a perforation pattern (3), at least some of the through-flow apertures (5) having a substantially polygonal basic cross-section. The filter clement is characterized in that the polygonal basic cross-section is in each case determined by a plurality of side lines (13) and a plurality of imaginary corners (6) defined in each case by side lines (13) extending in pairs towards one another. In the region of the imaginary corners (6), the two corresponding side lines (13) are connected to one another by a curved line (11).