Abstract: The film (F) fed to the packaging machine has a width suitable for wrapping articles whose sizes may vary over a wide range, and its width is made proportionate to the largest size of article which the machine can wrap. For the wrapping of articles whose dimensions are smaller than the maximum ones acceptable by the machine, the width of the film is modified as required to suit the dimensions of the article to be wrapped, by a pleating process (9-12-112-29-129-229) such that the longitudinal axis of the pleats lies in the direction of the length of the section of film introduced into the wrapping station.