Venetian blind ladder means are provided in which first and second cross elements (4,5) of each cross connections of the ladder are located whereby the height of the projection of every pair of elements on a plane through the longitudinal side member axes ranges between zero and slightly larger than the depth of the blind slat material and the distance between the side members (3a,3b) of the ladder is only slightly greater than the slat width. During assembly, the ladder means are guided so that, at the location of interlacing, each consecutive interlacing opening is angled to extend in a plane perpendicular to the plane of slat feed or at an angle so that the projection of the mutual spacing between elements (4,5) is this perpendicular plane is sufficiently large to allow the advancing slat (2) to be easily and rapidly fed therethrough.