Ask ten quilters whether to prewash and you will get two firm answers and a long argument. Both sides have a point, and the right choice depends on what you are making.
Here is what prewashing actually does, when it matters, when you can skip it, and a five-minute test that tells you whether a fabric's dye is going to run.
What prewashing does
Takes out the shrinkage
Cotton shrinks the first time it is washed, typically 2 to 5% in each direction, and batiks can shrink more. Prewashing removes most of that before you cut.
Rinses out loose dye
Deep reds, rich blues and batiks are the colours most likely to release dye. Better in the prewash than onto the white fabric next to them.
Removes the finish
New fabric carries sizing, a light finish from the mill. Washing it out is kinder for baby clothes and sensitive skin.
But softens the fabric
That same finish keeps new fabric crisp and stable. Washed fabric frays more, stretches more and is harder to cut precisely.
So should you?
| Prewash | You can skip it |
|---|---|
| Clothes, which must fit after washing | Wall hangings and items that will rarely be washed |
| Baby clothes, bibs and baby quilts | Quilts where you love the soft, crinkled look the first wash gives |
| Anything with reds or darks next to whites or pale colours | Projects made entirely from light, similar colours |
| Cushion covers and bags you will wash often | Small precuts such as charm squares, which fray and distort |
| Projects mixing different fabrics, which may shrink differently |
Our product listings say the same thing in short: pre-wash dark and bright colours before sewing them next to light ones.
The five-minute bleed test
Cut a 5 cm square of the fabric you are worried about.
Soak it in a glass of hot water for about five minutes. If the water turns coloured, the dye is loose.
Press the wet square onto a white paper towel. Any colour on the towel means it will bleed.
If it bleeds, prewash it on its own, with colour-catcher sheets, until the water runs clear.
How to prewash
1. Stop the fraying
Zigzag or pink the cut edges first, or the wash will unravel a long fringe of threads.
2. Wash as you will wash the project
Cool water and a gentle cycle, with darks and lights separated.
3. Dry
Most shrinkage happens in the dryer. If the finished item will be tumble dried, tumble dry the fabric; if it will be line dried, line dry it.
4. Press and starch
Press while slightly damp, and use spray starch to bring back the crispness for accurate cutting.
Crisp fabric again
Dylon Spray Starch
KES 3,000
After prewashing, a light spray of starch as you press restores the body that makes quilting cotton easy to cut and sew accurately. It also helps keep points sharp when piecing patchwork.
See spray starchFat quarters and small pieces
Small pieces tangle badly in a machine. Soak them by hand in cool water for 15 to 20 minutes, or wash them in a mesh laundry bag on a gentle cycle.
Related guides
Once your quilt is finished, our guide to washing and caring for a quilt keeps it looking its best. Planning a project? See how much fabric you need.
Questions about a fabric?
Ask us at our shop at Muthaiga Mini Market, or on WhatsApp, before you cut.
Shop quilting fabricOr message us on 0798 316 860
Sources: HC Quilts, All About Quilts, Nancy's Notions. Prices correct at the time of writing.
