How To · Fashion · Care
How to care for cotton and wool: the washing and storage rules that actually matter
Cotton and wool are the foundation of any functional wardrobe—and they demand opposite approaches. Learn the specific moves that preserve both without the fussy mythology.
5 min read · IrisCotton and wool are not interchangeable. Cotton is a plant fiber that loves water and heat; wool is a protein fiber that shrinks, pills, and felts when mishandled. The care labels exist for a reason, but they're often vague. Here's what actually happens when you wash them wrong—and how to avoid it.
The good news: both fibers are durable when treated with intention. You don't need special detergents or expensive machines. You need to understand the physics of each material and act accordingly.
Wool doesn't need washing as often as you think. Cotton can handle more aggression than you're probably giving it.
What you'll need.
- 01Washing machine with delicate cycle
- 02Wool-specific detergent
- 03Standard laundry detergent
- 04Clean towels for drying
- 05Cedar blocks or lavender sachets
- 06Steamer (optional but recommended)
- 07Wooden hangers
Step one · 2 minutes
Check the fiber content and read the label
Look at the tag. If it says 100% cotton, you have flexibility. If it's a cotton-blend with wool, silk, or linen, follow the most delicate fiber's rules. A 90% cotton / 10% wool blend behaves like wool. Blends are the exception to everything that follows.
Screenshot the care label with your phone before washing. You'll forget what it says.
Step two · 3 minutes
Wash cotton in hot or warm water with regular detergent
Cotton fibers tighten in cold water and relax in heat. Use the hottest water the label allows. Add a standard laundry detergent—nothing special needed. Turn the garment inside out to reduce fading and pilling on the visible surface. Wash with like colors to prevent dye bleeding on first wash.
New dark cottons will bleed. Wash them alone or with other darks for the first three washes.
Step three · 4 minutes
Wash wool in cool water with wool-specific detergent
Wool shrinks and felts when agitated in warm water. Use cool water (60°F or below) and a wool detergent that contains lanolin or a pH-neutral formula. Hand-wash or use the delicate/wool cycle on your machine. Never use regular laundry detergent—it's alkaline and opens the wool fiber's scales, causing matting. Wash wool inside out to reduce pilling.
If you don't have wool detergent, use a gentle shampoo. It's formulated for protein fibers, just like wool.
Step four · 2 minutes
Dry cotton flat or in the dryer; dry wool flat always
Cotton can handle machine drying on medium heat without damage. Air-drying extends the life of any garment. Wool must be dried flat on a towel or drying rack—never hang it wet, never machine dry it. The weight of water stretches wool fibers permanently. Reshape wool while damp if needed, then let it dry completely (6–12 hours).
Lay wet wool on a clean towel, roll the towel to remove excess water, then unroll it flat to dry. This speeds up the process without wringing.
Step five · 2 minutes
Store cotton upright or folded; store wool folded only
Cotton is strong and can be hung or folded without damage. Wool should always be folded to prevent stretching from its own weight. Use cedar blocks or lavender sachets in wool storage—they deter moths without the toxicity of mothballs. Store both in a cool, dry place away from direct sunlight, which fades fibers over time.
Fold wool along the seams to create natural creases that won't show. Hang cotton on wooden hangers if possible—plastic and wire can leave marks.
Step six · 2 minutes
Refresh wool between washes; spot-clean cotton stains
Wool doesn't need frequent washing. Hang it outside for a few hours to air out odors and refresh the fibers. For visible stains on wool, spot-clean with a damp cloth and wool detergent. For cotton stains, treat immediately with cold water and a stain remover before washing. Heat sets stains permanently, so never put a stained cotton garment in the dryer.
A steamer is your best friend for wool. It refreshes the fiber without water and removes wrinkles gently.
How to know it's working
Cotton should feel soft and maintain its shape wash after wash. Wool should remain supple without pilling, shrinking, or developing odors. Both fibers will show visible wear over years of proper care—that's aging, not failure.
Questions at the mirror.
My wool sweater shrank in the wash. Can I fix it?
Partially. Soak it in cool water with hair conditioner for 20 minutes to relax the fibers, then gently stretch it back to shape while damp. Lay it flat to dry. This works best on minor shrinkage. Severe felting is permanent.
How often should I actually wash these garments?
Cotton: every 3–5 wears, or when visibly soiled. Wool: every 5–10 wears, or when it smells. Wool is naturally antimicrobial and doesn't trap odor like cotton does. Overwashing both fibers is the main cause of premature wear.
Can I use fabric softener on cotton?
You can, but don't. Fabric softener coats fibers and reduces absorbency and breathability. Cotton works better without it. If you want softness, use wool dryer balls instead.
What's the difference between dry-clean-only wool and machine-washable wool?
Machine-washable wool is treated to resist felting and can handle gentle cycles. Dry-clean-only wool is untreated and will shrink in water. Follow the label. When in doubt, hand-wash in cool water with wool detergent.