Across the world a whole lot of gifts will get wrapped this week, and I’m gonna guess at least 50 percent of those will have ribbons. (the half wrapped by girls… but let’s face it, they’re probably doing the vast majority of wrapping anyways) The really fancy wrap jobs will also have those ribbons curled, and that brings us to today’s fact. Curling ribbons.
To be clear, I’m talking about plastic ribbons and the popular technique of scraping a blade of your scissors along the ribbon to create a permanent curl. The reason this happens is a molecular stretching of the plastic, but the outside of the ribbon (away from the blade) stretches more than the inside, producing the curl.
In that stressful action (for the ribbon only, I hope) the outer edge has a little bit further to travel. If you imagine breaking a branch. You hold on to the ends, and push with your foot on the middle. The branch always breaks on the outer side first. The inside of the branch has to curve around your foot, but the outside has to curve around your foot AND the inside portion of the branch. It has to stretch farther, and eventually breaks. Same deal with the ribbon, except the plastic stretches enough to avoid breaking.
A scientific study has shown that the best ribbon curls are produced with a slow stretch. I’ve seen some gift wrappers who rip along that ribbon like they are trying to start a lawnmower. However, the finest curls comes from a steady pace with consistent pressure. The reason for this is because the elasticity of the plastic can somewhat recover from a quick stretch, while the longer stretch leaves more permanent results.
