Foil stripes with built-in security elements, typically in the width of 0.8 to 5 mm, embedded into banknote and security paper. Options include fully embedded threads and windowed threads. For the embedding a cylinder mould paper machine is used. Security threads can include visual and functional surfaces, e.g. negative text by demetallization of an area, hologram, ColourShift, magnetic print, fluorescence, electrical conductivity, etc.