A security print contains a background pattern formed for example of dots or lines. An object, for example the text “BEWARE OF FORGERY”, is worked into this regular background pattern for copy protection. The text is worked in by the individual lines of the background pattern being split at the places where the text is located into two partial lines which are each only about half as wide as the original line. With the naked eye this split of the background pattern components is not, or barely, recognizable. When such an original security print is copied on a conventional copying machine the original, relatively wide lines of the background pattern appear on the copy but the partial lines formed by the split thereof are not, or very poorly, copied so that the text “BEWARE OF FORGERY” appears clearly in the copy.