If you ever pull out more Scotch tape than you need, you might as well forget trying to save it by rolling it back onto the roll. It’ll twist and stick to itself, your fingers, and the dispenser, and if it does actually get back on the roll it’s bound to be crooked and overlap at the edges. How on earth, then, do tape manufacturers make so many millions of perfectly rolled rolls of tape that drop neatly into dispensers in offices and homes around the world?
The trick is to roll the tape before it is cut into such a small, unmanageable size. Just as a newspaper is run through a press, sheets of polyester film or cellophane several feet in width are run through a machine where, rather than being printed, they are coated with adhesive. The sticky film is fed onto a long rolling rube, also several feet in width. This super-wide roll of Scotch tape is then subjected to a slitting machine, which consists of a bar with round knives of various sizes. Almost instantaneously these sharp knives whir through both the tape and the tube to make those familiar, compact rolls.