Submitted by Eric Daniel
100 mph tape, a.k.a. duct tape in the civilian world, is the military's best-kept battlefield secret. There is nothing 100mph tape can't fix. I've repaired rucksacks with it, hummer doors, radio antennas, patched holes in my poncho and gortex jacket with it, used it to keep my shoes on my feet and CS gas out of my pants, and more often than not nowadays, used it as a cost effective form of moleskin to ward of blisters. You should never find yourself abroad without a roll of 100mph tape in your pocket. Never.
This having been said, not all tape is created equal. Experience (failure in other words) has taught me that certain brands are better than others. The most effective I've found has been the OD green tape Nashua Tape produced by Covalence Adhesives. This particular brand is quite tacky, even in cold weather, tears easily with the fingers, and "irons" very well (when using 100mph tape to seal a fabric tear, I get the best results by taping over the tear and then using an iron to heat and soften the glue. When the heated tape cools, it will have formed a relatively permanent patch on the fabric (the most recent patch on my gortex is almost 5 years old.)