Short answer
In most cases, yes, washing fabric before sewing is a good idea, especially for washable natural fibers such as cotton and linen. There are exceptions, including fabrics that are dry-clean only, some precut quilting bundles and materials you will never wash. The key principle is to treat the fabric the way you plan to treat the finished item.
Why prewash
- Shrinkage. Many fabrics, particularly cotton, linen and rayon, can shrink the first time they are washed. If that happens after the piece is sewn, the fit can change or seams can pucker. Exact amounts vary widely by fabric and by how it is washed and dried, so the safest approach is to wash a sample and measure it.
- Dye. Some fabrics, especially deep or saturated colors, may release dye in the wash. Finding that out before sewing, rather than after, lets you wash it separately or decide not to pair it with lighter fabrics.
- Finishes and sizing. Fabric may carry starch, sizing or other finishes from manufacturing. Washing removes much of this and changes how the fabric feels and drapes, so you are sewing with the fabric as it will behave in use.
- Fabric relaxing. Washing can help the weave settle, which can make cutting and sewing more predictable.
- Comfort. Some people simply prefer to launder new fabric for garments and bedding before it touches skin.
When you might skip it
- Dry-clean-only fabrics such as many structured wools, silks or fabrics with fragile finishes. A steam press may be used to relax these instead, but check the bolt end or ask the seller.
- Items that won’t be washed, such as some decorative pieces.
- Precut quilt pieces and charm packs, which can distort or fray when washed. Quilters differ on this, and it depends on the project.
- Fabrics labeled pre-shrunk, though some sewists still wash to be safe.
- Stabilized or fused materials, or anything where water would damage a coating.
If you are unsure, cut a small square, measure it, wash it as you intend to care for the item, and measure again.
How to prewash
Prepare the edges
Cut edges can fray and tangle in the wash. To limit this:
- Zigzag or serge the raw edges.
- Trim them with pinking shears.
- Snip the selvage corners, or fold and baste the cut ends if fraying is a concern.
Stitching a quick edge before washing generally takes only a few minutes and keeps the yardage tidier.
Sort and wash
- Wash similar colors together, and wash very bright or dark fabrics separately.
- Use the same temperature, cycle and drying method you will use for the finished item. If in doubt, follow the fabric’s care guidance.
- A mild detergent is typically enough. Fabric softener is often skipped, as it can leave a coating that interferes with some finishes and with fusing interfacing.
- Don’t overload the machine, so the fabric can move freely and rinse well.
- Wash fabrics for one project together if they will be used together.
Dry
Machine drying or line drying should match how the finished piece will be cared for. Remove fabric while it is slightly damp where possible, to limit deep wrinkles. Note that high heat can shrink some fabrics more than air drying.
Press and inspect
Once dry, press the fabric flat with a heat setting appropriate for its fiber. Use pressing technique (see why pressing matters in sewing) to avoid stretching. Check the fabric for color change, tangled threads, or a grain that has gone off-square. Then lay out and cut. If you are marking pieces afterward, see how to mark patterns on fabric.
What to use for a prewash
A plain machine wash with a regular, mild detergent is the usual choice. Some sewists use a cold or gentle cycle for delicate fabrics, or hand wash. For fabrics where dye release is a worry, a small piece can be tested in a bowl of water first. Specialty products such as dye-catching sheets are available, and their instructions should be followed.
Fabrics needing extra care
- Wool: may felt or shrink with heat and agitation. Check the label or consider steaming instead.
- Silk and delicate rayon: often washed gently by hand, or not washed, depending on the type.
- Linen: commonly washed to soften and shrink it before sewing. See how to iron linen for after the wash.
- Knits: can shrink and also change in width and length, so wash before cutting if the item will be laundered.
- Interfacing: some brands recommend pre-shrinking fusible interfacing; others do not. Check the product instructions and see our sew-in interfacing guide.
FAQ
How do you prepare fabric before sewing?
Check the care instructions, finish the raw edges if you will wash it, wash and dry it as you plan to care for the finished item, press it, and then cut.
How do I prewash fabric without fraying?
Zigzag, serge or pink the cut edges first, and avoid overloading the machine.
What fabrics should not be washed?
Dry-clean-only fabrics, coated or fused materials, and fabrics whose labels advise against washing. Some precuts are also better left unwashed.
Do I need to prewash if the fabric is labeled pre-shrunk?
Not always, but small amounts of further shrinkage are still possible, so some sewists wash anyway.