Outerwear gets washed less often than anything else in a wardrobe, which is precisely why people get it wrong when they finally do. Nylon is tougher than it looks in water and far more fragile than it looks in heat. If you want to know how to wash a nylon jacket without shortening its life, the short version is this: cool water, gentle cycle, zips closed, and never the dryer. The longer version explains why each of those matters, and what to do when something has actually spilled on it.
Can 100% nylon be washed in a machine?
Yes, for an uninsulated shell. Close every zip and fasten every snap first — an open metal zip is the commonest cause of snags and pulled threads, because it drags against the drum and against the rest of the load. Turn the jacket inside out, wash it on its own or with soft items only, and use a gentle or synthetics cycle at 30°C. Use a small amount of liquid detergent. Skip fabric softener entirely: it leaves a film on synthetic fibres that dulls the matte finish and blunts any water repellency the shell had.
The one exception is a jacket with a bonded membrane, a taped seam or down fill. Those have their own rules and usually a specific detergent. Check the care label before you assume a shell is a plain shell.
Does 100% nylon shrink in the wash?
Barely, if the water is cool. Nylon is a synthetic filament and does not felt or contract the way wool does, so a 30°C wash leaves the dimensions essentially unchanged. What does change it is heat. Nylon begins to soften well below the temperature of a hot wash or a tumble dryer, and once a filament has relaxed under heat it sets in the new shape as it cools. That is the mechanism behind almost every shrunken, puckered or wavy-hemmed nylon jacket you have seen — not the water, the temperature.
Can you put a nylon jacket in the dryer?
Don't. This is the single rule worth remembering from the whole article. A tumble dryer runs hot enough to distort the fibre, warp the ribbed hem and cuffs, and permanently pucker the stitching along the seams. The damage is not reversible and it usually shows first at the waistband, where the rib and the shell are sewn together under tension.
Dry it instead on a broad hanger, zipped, away from a radiator and out of direct sun. A nylon shell is close to dry within a couple of hours indoors because the fibre absorbs very little water. Hang it while it is still faintly damp and most creases fall out on their own. This is how we would treat The Bomber Jacket, whose matte nylon face is exactly the surface a dryer would gloss and pucker.
How to remove stains from a nylon jacket
Deal with it locally before you commit the whole jacket to a wash. Nylon is not absorbent, so most spills sit on the surface for a few minutes rather than sinking in — that window is your advantage. Blot, never rub: rubbing drives the mark into the weave and can burnish the finish so the spot stays visible even once the stain is gone.
For a food or drink mark, use a damp cloth with a drop of liquid detergent, work from the outside of the mark inwards, then sponge with clean water to lift the detergent out. For grease, dab a little washing-up liquid on neat, leave it five minutes, then rinse. Let the area air-dry before you judge the result; damp nylon always looks darker than it will.
How to get wrinkles out of nylon
Not with an iron, at least not directly. A hot plate on nylon will glaze the surface and can melt it outright. If hanging has not solved it, hang the jacket in the bathroom while you shower and let the steam relax the fibre, or hold a steamer 15 to 20cm away and keep it moving. If you must iron, use the lowest synthetic setting, a pressing cloth between the iron and the shell, and test on an inside seam allowance first.
How often does a shell actually need washing?
Less often than you think. An outer layer rarely touches your skin, so it collects dust and the odd mark rather than body oils. Two or three washes across an autumn and winter is plenty for most people; spot-clean in between and air the jacket after a wet or smoky evening. Every wash costs a little of the finish, so the cheapest way to keep a shell looking new is simply to wash it less and hang it properly.
Knitwear worn underneath is the opposite case — it sits against the skin and needs a different routine altogether, which is worth knowing if you layer a jacket over something like The Alpine Crewneck or The Quarter-Zip Knit. The same cool-water, no-dryer logic applies to a lightweight women's shell such as The Solis Jacket, while a structured leather-look piece like The Monroe Blazer should be wiped rather than washed.
If you are still deciding which layer the day actually calls for, we work through that in what jacket to wear in 15 degree weather. Short answers to other fit, fabric and care questions are collected on Style Answers.