When buying a raincoat, you must decide whether you want it to be completely waterproof or merely water repellent. The most popular raincoat, a variation of the World War I trench coat, is usually made of poplin, a tightly woven fabric, treated with a water-repellent finish. Poplin coats supply some water resistance while letting the body breathe, but they get soaked in a prolonged downpour.
To prevent wrinkles and a musty smell, hang a wet coat on a wooden hanger and let it dry before returning it to the closet. Read the care label; some coats should not be dry-cleaned and others should not be washed. If you have a choice, machine wash the coat twice; once with soap and once in clear water. Press the garment yourself or have it pressed professionally.
A water-repellent finish will eventually wear out (when depends on the amount of wear and cleaning it gets). If you notice that water sinks into the fabric instead of rolling off, retreat the coat with a water-resistant spray, or ask your cleaner to do so.
If you want a truly waterproof coat, get a slicker made from a nonporous material such as rubber or vinyl. A garment made of ripstop nylon coated with polyurethane makes a very light-weight waterproof covering.
Completely waterproof garments usually don’t breathe; when you’re wearing one your clothes and body can get overheated and sweaty. A poncho solves this problem; it covers well and yet allows for circulation of air.
Even in nonporous garments, water can leak through the seams. Buy a slicker with flat-felled seams and seal them with liquid sealer, or look for a garment with seams that have been welded (fused) to the garment.
PTFE, a relatively new fabric, is both breathable and waterproof-PTFE is a microporous film that allows perspiration vapor to pass from inside to the outside but keeps moisture from passing from the outside in. The film is either laminated to a single layer of nylon or other fabric or sandwiched between two layers. It is best to add a coat of sealant to the seams. PTFE garments, although expensive, are ideal for anyone who spends a good deal of time outdoors.