How to Unshrink a Cashmere Sweater

Can You Actually Unshrink Cashmere?

It depends on the type of shrinkage. Cashmere shrinks through two different mechanisms, and only one is reversible:

Relaxation shrinkage (reversible): The fibers contracted when wet and set in a shorter position during drying. The knit structure is intact — the stitches just tightened up. This typically causes 5-15% shrinkage and responds well to the soaking-and-stretching method below.

Felting (permanent): The microscopic scales on the fiber surface locked together under heat or agitation, fusing the fibers into a dense mat. The knit structure is destroyed. The sweater feels thick, stiff, and matted. Felting cannot be reversed by any home method.

How to Tell Which Type You Have

Check	Relaxation Shrinkage	Felting
Texture	Still soft, knit pattern visible	Stiff, dense, matted
Knit stitches	Individual stitches still visible	Stitches blurred or invisible
Thickness	Same or slightly thicker	Noticeably thicker and denser
Stretch test	Fabric stretches when pulled gently	Fabric resists stretching
Size reduction	5-15%	20-50%

If your sweater passes the stretch test — the fabric gives when you pull gently — the method below has a good chance of working.

The Soaking and Stretching Method

What You Need

• A basin or sink large enough to submerge the sweater
• Cold water
• Hair conditioner or fabric conditioner (about 2 tablespoons)
• Two large clean towels
• Rust-proof pins (T-pins or stainless steel sewing pins)
• A flat surface you can pin into (a blocking mat, carpet, or thick towel on a table)

Step-by-Step Process

1. Soak in conditioner solution. Fill the basin with cold water and add 2 tablespoons of hair conditioner (any basic conditioner works — nothing with heavy silicones). Submerge the sweater and gently press it into the water. The conditioner lubricates the fibers and allows them to slide past each other more easily during stretching.
2. Soak for 30 minutes. Leave the sweater undisturbed. The conditioner needs time to penetrate the fiber structure.
3. Remove without rinsing. Lift the sweater out, supporting its full weight. Do not rinse — leave the conditioner in. Press gently between towels to remove excess water. The sweater should be damp but not dripping.
4. Stretch gently. Lay the sweater flat on your blocking surface. Starting from the center, gently pull the fabric outward in all directions. Work slowly and evenly — small increments, not aggressive pulls. Focus on the areas that shrank most (usually the body length and sleeve length).
5. Pin to hold. Once you have stretched the sweater to its original dimensions (or as close as you can get), pin the edges to the surface. Pin every 2-3 inches along the shoulders, sides, hem, cuffs, and neckline. The pins hold the sweater under tension while it dries, preventing it from contracting back.
6. Dry completely. Leave pinned until fully dry — 24 to 48 hours depending on humidity. Do not use heat to speed drying. The fibers need to dry slowly under tension to set in the new (restored) shape.
7. Rinse the conditioner. Once dry and unpinned, hand wash gently in cold water to remove the conditioner residue. Dry flat again, reshaping as normal.

Realistic Expectations

Shrinkage Amount	Recovery Likelihood	Notes
5-10% (half a size)	Very good	Full recovery is common with one treatment
10-15% (one size)	Good	May need two rounds of soaking and stretching
15-20%	Partial	Some recovery but likely will not reach original size
Over 20%	Unlikely	This level of shrinkage usually involves felting, which is irreversible

What If It Does Not Work?

If the sweater does not stretch or springs back after unpinning:

• Try again with more conditioner — increase to 3-4 tablespoons and soak for 45 minutes. Some fibers need more lubrication to release.
• Try a dedicated wool softener — products like Soak or Eucalan are formulated specifically for animal fibers and may work where generic conditioner does not.
• Accept partial recovery — a sweater that went from a Medium to an XS may only recover to a Small. Partial recovery is still better than no recovery.
• Repurpose — a severely felted cashmere sweater makes excellent material for craft projects, cashmere patches for repairing other sweaters, or cashmere accessories (cut and sewn into mittens, headbands, or scarves).

How to Prevent Shrinkage

The best treatment is prevention. Cashmere shrinks because of three triggers — avoid all three and shrinkage never happens:

• Hot water: Always use cold water (below 30°C / 86°F) for washing
• Agitation: No wringing, twisting, or rubbing when wet. Use a wool cycle if machine washing.
• Heat drying: Never tumble dry. Always lay flat at room temperature.

For the full science behind cashmere shrinkage, see our cashmere shrinkage guide.