How to Keep Black Pants Black

Black pants go grey gradually, and the cause is usually several small habits rather than one mistake. The good news is that every one of them is easy to change.

What actually fades black fabric

• Friction. Fibers rubbing against each other, the drum and zippers break off tiny bits of dyed surface. The fabric looks lighter because it's slightly fuzzy.
• Heat. Hot water and high dryer heat help dye leave the fiber.
• Detergent residue. Too much detergent can leave a film that looks dull and chalky on dark fabric.
• Sunlight. UV breaks down many dyes. Drying black pants in the sun is a quick way to make them brown-ish.
• Chlorine bleach, including the bleach in some all-in-one detergents and a few stain removers.

What to do instead

1. Wash them inside out. The inside takes the friction. The outside stays dark.
2. Use cold water. Modern detergents work well cold, and cold water holds dye in better.
3. Use a detergent made for darks, or at least one without optical brighteners. Brighteners are designed to make whites look whiter and can leave a slight haze on black.
4. Use less detergent than you think. Follow the dose on the cap for the load size, not the size of the cap.
5. Choose a shorter, gentler cycle. Less time tumbling means less friction.
6. Wash with other darks, and keep lint-shedding items like towels out of the load.
7. Skip the dryer, or use low heat and pull them early. Dry indoors or in shade.
8. Wash less often. Air them out between wears. Spot clean small marks.

Myths worth dropping

Vinegar sets the dye. Vinegar is used to help fix certain dyes on wool and silk in dyeing processes. Commercially dyed cotton pants are colored with dyes that don't work that way, and a splash of household vinegar in the wash won't lock them in. It may help rinse out detergent residue, which can make fabric look slightly less dull. That's about all.

Salt stops bleeding. Salt is used during some dyeing processes, not after. Adding it to your wash doesn't fix the dye in finished garments.

Coffee or black tea redyes them. It stains them brown. Slightly. Unevenly. No.

When they've already faded

A fabric dye made for the fiber can restore black cotton reasonably well. Synthetic blends and polyester are much harder to redye at home. Either way, redyeing is a project. Prevention is easier.

What I do

Black and dark pants get turned inside out, washed cold in a detergent suited to darks, and kept out of high heat. They go home looking the same color they arrived. I can't make them darker than they arrived. I'm working on accepting that.