One day while making my duct tape wallets, it dawned on me that I didn’t know what made up this amazing stuff nor why it was created. These questions plagued me for days, so I set out to find the answers. Below is a synopsis of what I discovered:
What is Duct Tape?
Duct tape is a pressure sensitive tape that is comprised of three layers. The top layer is 
typically Polyethelyne, which is a type of plastic. The middle layer is a fabric mesh, and the bottom layer is a rubber-based adhesive (see figure to the right, courtesy of The Duct Tape Guys). The combination of these three layers create a durable, waterproof tape that can be ripped by hand (no other tools required). To increase strength and quality, manufacturers increase the number of fibers that make up the fabric mesh. One type of duct tape is reported to be so strong that when doubled over on itself, it can pull a 1 ton car!
Why was Duct Tape Created?
Believe it or not, duct tape originally had nothing to do with connecting and/or sealing ducts. It all started in 1942 during WWII. Permacel, at that time a division of Johnson & Johnson, was charged by the military to create a strong, waterproof tape to seal ammunition cases. They applied a rubber-based adhesive to cotton duck and added a waterproof sealant, which created a tape that has the same properties we love about the stuff today. It originally had the name of “Duck Tape” due to the waterproof properties (like a duck’s feathers) and possibly due to the use of cotton duck. Soldiers soon found that the tape was extremely useful for making quick repairs to jeeps, guns, aircraft, etc. and for making crude bandages.
After the war, soldiers brought their beloved “duck tape” home with them, where it began to be used in the booming housing industry as a way to connect HVAC ducts. The color was soon changed from olive green to sheet metal gray to match the ductwork, and people forevermore referred to the tape as duct tape (except Duck® Brand, who formally registered “Duck Tape”).
A Word of Caution
Though the name is deceiving, duct tape shouldn’t be used as permanent means to seal ductwork. Used on ducts, it has a low life expectancy and becomes brittle, which may cause catastrophic failure. However, duct tape is great for a brief, temporary fix until the proper specialty tape or sealant can be applied.
