A method of making slider-actuated string-zippered packages. The method can be applied on a form-fill-seal machine or a machine that makes packages without filling, and involves transverse application of string zipper material on packaging film. One disclosed method comprises the following steps: (a) interlocking respective lengths of first and second flangeless zipper strips to each other; (b) advancing a first web in a machine direction; (c) joining a back of at least a major portion of the length of first flangeless zipper strip to the first web of packaging film along a zone that is oriented transverse to the machine direction; (d) laying a second web over the first web with the major portion of the length of first flangeless zipper strip and a major portion the length of second flangeless zipper strip disposed between the first and second webs; (e) joining a back of at least the major portion of the length of second flangeless zipper strip to the second web; (f) joining the second web to the first web to form a pocket having a mouth that is closed to the extent the major portions of the lengths of first and second flangeless zipper strips are interlocked; (g) cutting the first and second webs along respective lines close to the lengths of first and second flangeless zipper strips respectively; and (h) inserting a slider on the lengths of first and second flangeless zipper strips with the first and second webs joined thereto.
