Most people have encountered a stuck zipper at some point without panic, since they can often simply be tugged free from the zipper's teeth without damaging the fabric. Occasionally, fabric is stuck too deeply into the zipper, and can't simply be yanked out, and a home remedy is in order. Most homes regularly stock the supplies needed to begin working with a difficult zipper.
Things You'll Need
Paraffin, bar soap, or candle wax
Graphite pencil, sharpened
Salt water, vinegar, or cola
Tug gently at any piece of fabric that has gotten caught between the zipper teeth without moving the zipper up or down (which risks making the problem worse).
Apply paraffin, bar soap, or candle wax to the zipper with a cotton swab, in particular on the area directly below, above, and on the zipper tab. This acts as a natural lubricant for the zipper to slide on.
Lightly press a pencil to the teeth of the zipper and apply a small layer of graphite. The goal is not to cover it completely with graphite, because it may leave particles between the teeth that will give the zipper more to jam on.
Soak your garment, in particular the zipper area, in salt water or vinegar (three hours), or cola (less than an hour) to remove rust particles from the zipper and corrode anything jamming the way. Apply your cleaner of choice to a small area in an unnoticeable place to test for undesirable effects such as discoloration or fabric damage.
An occasional application of paraffin, bar soap or candle wax will offer protection beyond simply getting a zipper unstuck, such as rust protection and ease of movement.
Use care with soft fabrics, since a rip is more permanent than a malfunctioning zipper.