Volume 28, Issue 3 (July 1983)
Physical Comparison of Plastic Garbage Bags and Sandwich Bags
Individual marks are located adjacent to machine-cut ends on garbage bags and sandwich bags. Class marks that change direction or width or both are present on many brands. The cut ends of plastic bags can successfully be related to each other. Visits were made to plants that manufacture both types of bags to observe the production methods and sequence. Consecutively made samples were collected and others purchased at retail outlets. All were compared with optical equipment and some with photographic techniques to enhance faint characteristics. Results obtained using the techniques described were presented in court.