Still have some last-minute shopping left to do? Not to worry: With advice from engineers at the University of Rochester, those recently wrapped gifts will appear to be the finest under the tree.
Members of the Mechanics of Flexible Structures Project offer these tips for creating finely wrapped gifts:
KEEP GIFTS AWAY FROM HEAT. While heat won't affect the wrapping paper itself, heat will make the glue (a type of polymer) creep, causing wrapping paper that has been pulled tightly over the package to sag. The higher the temperature, the more rapid the creep, say graduate student John LaFleche. You may even decide to wait until Christmas Eve before wrapping your gifts so the paper won't have time to sag.
AVOID HUMIDITY. In other words, don't store your gifts near a humidifier or in a damp basement. Excess humidity will make wrapping paper curl and take away that sharp, crisp look.
USE ENOUGH TAPE. This is important so that no one section of the paper is under too much stress. "Don't use only one small piece of tape to wrap a present really tightly," says graduate student Kenneth Stack. "Distribute the load over as wide an area as possible. Paper rips not just because you've wrapped it too tightly, but because you've put all the force in one spot."
CONSIDER INVESTING in some thick or coated wrapping paper. The thicker the paper, the less likely it will be to wrinkle. Stack says that using a double-thick piece of wrapping paper makes the gift eight times less likely to wrinkle. Thicker paper is also more resistant to tearing.
IF YOU'RE A KLUTZ and never seem to be able to wrap a wrinkle-free gift, consider having your gifts wrapped for you.
The Mechanics of Flexible Structures Project is headed by Richard Benson, professor of mechanical engineering. The group studies flexible structures such as paper, contact lenses, magnetic tape and disks found in computers and VCRs, the shrink- wrap material used in digital color printers, and even IV bags used in hospitals. The group's support comes from companies such as Eastman Kodak, Xerox, and Hewlett-Packard. tr