The security substrate comprises an at least partially light transmitting carrier supporting a security feature and the security feature comprises at least first and second layers at list one of which covers an area which is less than a full surface area of the carrier and which at least partially overlaps the other layer. The layers have substantially the same color and texture and the reflective contrast ratio of the overlapping areas and the non-over lapping areas is less than 20 % and the transmissive contrast ratio of the overlapping areas and the non-overlapping areas is greater than 3 %.
