In silver or black or in transparent and colored models, whichever way you want it, the duct tape is used for any purpose that requires good adhesion and waterproof sealing.
It is made with vinyl then strengthened with fabric.
It was first used by the military due to its ability to repair all sorts of materials like guns, cars and even air crafts.
As necessary as it is in the household for general repairs, it's also as quite needed in engineering because of its flexibility, strength and uniformity.
The quality that makes it a must-have is its ability to resist grease and oils which then makes it automatically waterproof! However, it has failed to impress in the entertainment industry and the efforts which were made to introduce it proved not as successful as was intended.
Did you know that this duct tape has actually been used to save lives? If you know your history, you'll understand well why NASA projects have found it extremely vital especially after Apollo 13 in the 70s and later Apollo 17 when it was used by astronauts to repair the spacecraft! Without this device, certain projects would have proved a hard nut to crack but it came to the rescue.
It has been used in many ways and a case in example is a designer who used the duct tape to make a prom dress and handbag, and not just one but many! Others have used it to make wallets, belts, etc.
However, as much as it sounds useful, you should never even at one time attempt to use it in electrical applications.
Use the right tools and who knows, you might also save a life.