Used daily in the shipping department. Of these three items, the Carton Sizer Tool is probably the least known. Ruled for precise measuring, the Carton Sizer is used to lower the depth of a box, thereby reducing the amount of void fill needed. In essence, the Sizer tool makes a score line or crease into all four interior side walls at the identical point from the top edge of the box. Use a box knife to cut all four corners from the point of the score line to the top edge of the box. Then, fold inward the top section of each side wall, cutting off any overlapping material. The end result is a lower depth box for your contents.