How to Remove Mold from Silk (and When to Stop Trying)

The scarf went into a plastic bin last September. In June you lift the lid and the smell gets there first: old basement and wet cardboard, then a scatter of gray freckles along one fold.

Don't shake it out, and don't carry it through the house. Moldy silk can often be saved, but the method is slower and plainer than most online advice, because the strongest mold killers in your laundry room are also hard on silk.

Can you get mold out of silk?

You can usually remove the growth, but a stain may stay. Mold feeds by digesting what it grows on, and the Canadian Conservation Institute warns that some marks are permanent. Cotton and linen are more vulnerable than silk, but silk is affected too.

Before you start, decide whether this is a home job. Skip straight to a professional if the label says dry clean only, if the piece is vintage, hand-painted or irreplaceable, or if the mold came with floodwater or sewage.

Is it safe to clean moldy silk yourself?

A few spots on a scarf or pillowcase are generally a job you can do yourself, with basic protection. The EPA notes that mold can trigger allergic reactions, asthma attacks and irritation of the eyes, skin and airways. Wear an N-95 respirator, gloves and goggles without vent holes, and work outdoors. If you have asthma, allergies or a weakened immune system, ask your doctor first, or hand the job to someone else.

How do you remove mold from silk?

Dry it, clean off the growth outdoors, test it, then wash it cold.

1. Bag it for the walk outside. A plastic bag keeps spores out of the house on the way, and that's all it's for.
2. Dry it completely. Hang it or lay it on a clean towel, in the shade, on a dry day. If you can't work outdoors, use a fan or a dehumidifier in a closed room. No clothes dryer and no direct sun, whatever old mildew remedies say: sun can fade and weaken silk.
3. Remove what you can. Still outside, brush gently with a soft, clean brush, or use a vacuum with a HEPA filter, a piece of fine screen over the nozzle and the nozzle held just above the cloth, as the Canadian Conservation Institute advises. Go over the whole piece, including the parts that look clean.
4. Test a hidden seam. Mix a little mild detergent into cold water and dab it on with a white cotton swab. Wait a few minutes, then blot with a white cloth. If any color comes off, stop here and see a cleaner.
5. Wash it cold. Hand wash it, or machine wash it on a gentle cycle in a mesh bag with mild detergent, on its own. By hand is better here, since you can watch the color and the stain.
6. Dry it again. Press the water out in a clean towel, then hang it or lay it flat, out of direct sun. Do not tumble dry.
7. Check it once it's dry. If the mark is fading, one more wash is reasonable. After that, stop.

Can you use bleach or hydrogen peroxide on moldy silk?

No. Chlorine bleach damages silk, as Ohio State University Extension's fact sheet says plainly.

Hydrogen peroxide takes more explaining, because so many websites call it gentle. It's still a bleach. Textile mills use it to whiten silk under controlled conditions, and studies find silk loses strength as the concentration, heat and time go up. On dyed or printed silk it can lift the color along with the stain. Dry-cleaning trade advice is to avoid all bleaches on protein fibers, and our care line says not to bleach. We couldn't find a conservation or university source behind the home dilutions you see online, so we won't give one. On a white piece worth saving, let a professional decide. Mildew sprays from the hardware store are made for hard surfaces, so keep them off silk too.

When should you stop and see a professional cleaner?

Stop if color moves during the spot test, if the stain or smell survives two washes, or if the silk feels thin or tears when tugged gently. Tell the cleaner it's mold and what you've already tried. For an heirloom, a textile conservator is the better call, and the American Institute for Conservation has a searchable directory. An everyday pillowcase that has gone weak or still smells musty has done its job, and it's fine to retire it.

How do you keep mold off silk?

Keep silk clean, completely dry and out of damp, still air. Mold is encouraged by relative humidity of 65% and up, warmth and poor air flow, and at 90% it can appear in days. The EPA advises keeping indoor humidity below 60%, ideally between 30% and 50%, and an inexpensive hygrometer will tell you where a closet stands. In a humid Gulf Coast summer or a damp basement, that closet may need a small dehumidifier, or at least an open door.

Wash silk before you store it, let it dry all the way through, and keep it in something that breathes. Our guide to storing silk covers the details, and why silk deteriorates explains what damp does over the long term.

Replacing a scarf that didn't make it? See LS Silk scarves →

That plastic bin held last September's damp all winter, with nowhere for it to go. Give next year's scarf a cotton bag and a shelf with some air around it, and the smell of old basement can stay in the basement.

Frequently asked questions

Does mildew ruin silk?

Not always. Light growth caught early can often be cleaned off, although it can leave a permanent mark. Heavy or long-standing growth can stain and weaken the fabric, and at that point the piece may not be worth saving.

How do you get a musty smell out of silk?

Air it outdoors in the shade until it's fully dry, then wash it cold with mild detergent and dry it again out of direct sun. If you can still smell mold after two washes, take it to a professional cleaner or retire it. Don't mask it with perfume or fabric spray.

Can you dry clean moldy silk?

Yes, and for dry-clean-only or valuable pieces it's the better route. Let the piece dry fully first, and carry it in a clean bag. Tell the cleaner it's mold, so they can decide how to handle it.

Will sunlight kill mold on silk?

Don't rely on it. Sun is the old standby for mildew on cotton, but it can fade silk, yellow white silk and weaken the fiber. Dry silk outdoors in the shade instead.

Should I throw away a moldy silk pillowcase?

Try the steps once if the growth is light and the silk still feels strong. If it stays musty after two washes, feels thin or tears easily, retire it. Anyone with asthma or a mold allergy should be stricter about that, and can ask their doctor.

Related reading: Why Does Silk Smell? · Do You Need to Dry-Clean Silk? · How to Remove Sweat, Deodorant or Makeup Stains from Silk