Venetian blinds include a pair of slat lift and guide tapes (27, 28) that extend from the upper rail (12), downwardly through openings (22) in the elongated parallel slats (14) and into the lower rail (13) where they are collected in the lower rail on spools (48). The lift and guide tapes are concave in cross section when in their rectilinear shape and progressively change to flat in cross section as they are pulled into the lower rail and wrapped about tape collector spools.