Yes, wash most fabric before you cut and sew it

Most fabric shrinks when it gets wet and warm, and that shrinkage happens the first time you wash a finished garment. If you sew with unwashed fabric, your finished piece will shrink after the first wash, making seams pucker, hems ride up, and fitted pieces no longer fit. Washing fabric before you sew — called preshrinking — lets the fabric shrink before you measure and cut, so the finished garment stays the size you made it.

The amount of shrinkage varies by fiber type and how the fabric was made. Cotton and linen shrink more than synthetics. Knits shrink more than wovens. A cheap cotton print might shrink 3 to 5 percent; a high-quality linen might shrink 2 to 3 percent. That means a piece of fabric 40 inches wide could become 38 to 39 inches wide after washing. For a fitted shirt or pair of pants, that difference shows.

The exception is fabric labeled preshrunk or sanforized, which has already been treated to prevent shrinkage. Even then, some residual shrinkage can occur, especially in natural fibers. If the label says preshrunk and you trust the maker, you can skip washing. For everything else, wash it.

Key Takeaways

  • Unwashed fabric shrinks during the first wash after you sew it, which distorts seams, hems, and fit, so preshrinking before cutting prevents this problem.
  • Cotton, linen, and other natural fibers shrink 2 to 5 percent; synthetics shrink less, and knits shrink more than wovens of the same fiber.
  • Wash fabric in the same water temperature and method you will use for the finished garment — hot water for towels, cold for dark colors, gentle cycle for delicates.
  • Dry fabric the same way you plan to care for the finished piece: machine dry on low heat, air dry, or lay flat, depending on the fiber and the garment's purpose.
  • Preshrunk and sanforized fabrics have been treated to resist shrinkage, but some residual shrinkage can still occur in natural fibers.

How much your fabric will actually shrink

Shrinkage depends on the fiber content and the fabric's construction. Cotton typically shrinks 2 to 5 percent in the first wash, with cheaper, looser-weave cottons shrinking more than tightly woven ones. Linen can shrink 3 to 5 percent, especially if it has not been preshrunk by the mill. Wool shrinks unpredictably and can felt if washed in hot water or agitated, so wool usually needs cold water and gentle handling. Synthetic blends — polyester, acrylic, nylon — shrink less than natural fibers, often 1 to 2 percent or less.

Knit fabrics shrink more than woven fabrics of the same fiber because the loops that make up a knit can compress more easily than interlocked threads. A cotton jersey knit might shrink 5 to 7 percent lengthwise and 2 to 3 percent across the width. A cotton poplin woven might shrink only 2 to 3 percent in both directions.

The only way to know your specific fabric's shrinkage is to wash a small piece before you buy or cut. Cut a 10-inch square, note its exact dimensions, wash and dry it the way you plan to care for the finished garment, and measure it again. The difference tells you what to expect. If you are buying yardage at a store, ask the staff whether they know the shrinkage rate for that particular bolt.

Wash fabric in the same conditions as the finished garment

The water temperature and wash method matter because they determine how much the fabric shrinks. If you plan to wash a finished garment in hot water, wash the fabric in hot water. If the finished piece will be hand-washed or dry-cleaned, preshrink in those conditions instead. This way, the fabric shrinks the same amount before and after sewing, and you avoid surprise shrinkage later.

For most cotton and linen garments, use warm or hot water with regular detergent. For dark colors that might bleed, use cold water. For delicate fabrics like silk or wool, use cold water and a gentle cycle or hand-wash. Add a small amount of detergent — you are not trying to clean the fabric, just let it move freely in water so it shrinks evenly.

Do not use fabric softener or bleach when preshrinking, because these can affect how the fabric behaves later. Softener can coat fibers and prevent future dyes or finishes from setting properly. Bleach can weaken fibers or change color. Plain water and mild detergent are enough.

Drying method affects shrinkage as much as washing does

How you dry fabric matters as much as how you wash it. Machine drying on high heat causes more shrinkage than air drying. If you plan to machine-dry the finished garment, machine-dry the fabric on the same heat setting. If you plan to air-dry, air-dry the fabric. This keeps the shrinkage consistent between preshrinking and future washes.

For cotton and linen that will be machine-dried, use medium or low heat rather than high, because high heat can damage fibers over time and causes more shrinkage than necessary. Remove the fabric while it is still slightly damp and lay it flat or hang it to finish drying. This prevents over-drying and excessive wrinkling.

For delicate fabrics, lay them flat on a clean towel or hang them to air-dry completely. Do not wring or twist them, because that can distort the weave and cause uneven shrinkage. Reshape the fabric gently while it is still damp so it dries in the correct dimensions.

When you can skip preshrinking

Fabric labeled preshrunk, sanforized, or shrink-resistant has been treated by the mill to prevent most shrinkage. These labels mean the fabric has already been through a controlled shrinking process, so additional shrinkage should be minimal — usually less than 1 percent. For garments where small changes in size do not matter much, like a loose t-shirt or a drawstring bag, you can often skip washing preshrunk fabric.

However, even preshrunk fabric can have residual shrinkage, especially in natural fibers like cotton or linen. If you are making something fitted or where exact dimensions matter — a pair of fitted pants, a tailored jacket, or a quilt — preshrink even preshrunk fabric to be safe. The extra step takes 30 minutes and prevents a ruined garment.

Synthetic fabrics like polyester or nylon shrink very little and rarely need preshrinking. If the label says the fabric is 100 percent polyester and preshrunk, you can usually skip washing. Read the label and use your judgment based on the garment you are making and how much shrinkage would matter.

Fabric that bleeds color needs special handling

Dark-colored fabrics, especially reds, blues, and blacks, sometimes bleed dye into the water during the first wash. If the dye bleeds onto other fabric pieces while they are wet, it can stain them permanently. To preshrink fabric that bleeds, wash it separately in cold water, or wash it with a dye-catcher product designed to trap loose dyes in the wash water.

You can test whether fabric bleeds by wetting a corner with cold water and rubbing it on a white cloth. If color comes off, the fabric bleeds. Wash it separately the first time, in cold water, and check the rinse water. If it is still colored after the first wash, rinse again. Most fabric stops bleeding after two or three washes.

Do not mix bleeding fabric with other pieces during preshrinking. Wash it alone, or wash it with other dark colors that also bleed. This prevents dye transfer and keeps your other fabrics clean.

Frequently Asked Questions

What if I forgot to preshrink and the finished garment shrank?

You cannot undo shrinkage, but you can prevent it from happening again. Wash the garment in cold water on a gentle cycle and air-dry it flat to minimize future shrinkage. For future projects, preshrink all fabric before cutting. If the garment is unwearable, you can sometimes use the pieces for a smaller project or donate it.

Do I need to preshrink fabric for a quilt?

Yes, especially if the quilt will be washed. Preshrink all fabric, including batting if it is cotton, in the same water temperature you plan to use for washing the finished quilt. Uneven shrinkage between pieces can cause puckering and distortion in the finished quilt.

Can I preshrink fabric by steaming instead of washing?

Steaming does not preshrink fabric the way water does. Shrinkage happens because water penetrates the fibers and heat causes them to contract. Steaming adds moisture and heat but does not fully replicate a wash cycle. Wash fabric in water for true preshrinking.

How long does preshrinking take?

Washing takes 30 to 45 minutes, and drying takes 1 to 3 hours depending on the drying method and fabric weight. Plan to preshrink fabric the day before you cut so it has time to dry completely. Damp fabric is harder to measure and cut accurately.

Does preshrinking make fabric softer?

Washing can soften fabric slightly by removing sizing — a starch-like coating applied during manufacturing. However, preshrinking is not meant to soften fabric; it is meant to prevent shrinkage. If you want softer fabric, use a gentle detergent and avoid fabric softener, which can interfere with dyes and finishes.