What is Prewashing?
Prewashing is the act of laundering your fabric before you use it in a project. This step typically takes place before anything else. But not everyone does it. To prewash or not to prewash is a personal preference and there are pros and cons to both methods. For one, fabric typically shrinks a bit in the wash. Which could be a pro if you’re sewing a garment (to ensure it fits perfectly once you sew it) or a con if you need to meet a quilt pattern fabric requirement and can’t afford to lose an inch.
Should I PreWash?
It’s up to you, but there are a couple things you should know.
If you Prewash your Fabric…
- It will shrink a bit. In both directions. And it could be anywhere from ¼-inch to a few inches depending on the fabric. Some fabrics like flannel and linen tend to shrink more than cotton. if you’re unsure how much your fabric will shrink, you can always launder a test swatch and see what happens. Otherwise order a little extra fabric and be prepared to lose a couple inches in the length and the width. Check out Facts About Fabric Grain to understand the difference between lengthwise and crosswise grain of fabric.
- The edges will fray. The cut edges of your fabric will fray, the selvedge sides less so (see Facts About Fabric Grain if you need a reminder about the difference). So after you prewash your fabric, you’ll need to trim all those pesky threads off before you go any further.
- So don’t prewash small pieces. The smaller the piece of fabric, the less suitable it is for prewashing. Small pieces of fabric typically don’t have enough surface area to withstand shrinking and fraying (see scraps in the “after prewashing” image below). Skip prewashing anything smaller than a fat quarter (like jelly roll strips, layer cake squares, charm pack squares and scraps). If you do choose to prewash smaller cuts, toss them in a mesh laundry bag so you don’t end up with a tangled ball of thread when you go to retrieve them from the dryer.
- It takes time. Washing, drying, trimming loose threads, ironing out the wrinkles and starching the crispness back into your fabric takes time. No question there.
- It removes excess dyes. Ever washed a load of white towels with a red shirt? While many modern fabrics are colorfast (meaning they’ll keep their color without fading or running when washed), vivid dyes like red, purple and blue can still bleed onto lighter colored fabrics in the wash. Prewashing vibrant fabrics can help remove excess dyes to prevent them from bleeding onto other fabrics in your final project.
- It removes manufacturing chemicals. Fabrics can be treated with a variety of substances to keep them looking bright and stiff on the bolt, which can sometimes irritate sensitive skin. While prewashing can help remove irritating chemicals, it also washes out the sizing (the stiffening treatment), leaving your fabric more relaxed and limper than before you tossed it in the wash.
- It helps to minimize shrinking of your final project. If you preshrink all of your fabrics before you turn them into a masterpiece, you’ll have less to worry about when you wash your final project. Upon a second wash, shrinkage should be minimal. And any shrinking that does occur, should happen consistently across fabrics.
If you do NOT Prewash your Fabric…
- You can use your fabric right away. By skipping the prewash step, you can dive right into your fun new project. And who doesn’t love that?
- You’ll have more time on your hands. No washing, drying, ironing, trimming or starching here!
- You run the risk of unexpected shrinking. If you choose not to prewash your fabrics and they shrink at different rates, things could get wonky. Being consistent in the type of fabric you use in a project (even better if it’s from the same manufacturer) can help minimize this risk.
- And the possibility of brightly colored dyes bleeding: If you have vibrant reds, purples and blues alongside bright white fabric in your quilt, there’s a possibility that they could bleed together in the wash.
- Your finished quilt will have that vintage crinkle: When you do finally wash your finished quilt, you’ll get that beautiful post-launder crinkle effect, which happens when fabrics that’s been stitched together shrinks up in the wash. I find that my quilts still get this gorgeous crinkle effect even when I prewash my fabrics.
Tips for Prewashing
Before you prewash your fabric, here are a few things to consider.
- Treat the edges of your fabric to minimize fraying. Consider trimming the edges with pinking sheers (do not clip the selvage sides), clipping the corners of the cut sides to make it more difficult for loose threads to escape. or stitching a zigzag stitch along the edges to stabilize loose threads.
- Use cold water. Wash your fabric in cold water to help to minimize shrinking.
- Wash like colors together. And don’t overcrowd your machine.
- Use a color catcher to absorb loose dye. These magical sheets can be found in the laundry aisle at the supermarket and act as dye magnets in the wash.
- Use a mesh laundry bag for smaller pieces. Mesh bags can help keep smaller pieces together so they don’t get lost or wound around other pieces in the wash.
- Remove fabric from the dryer promptly. Pulling fabric out of the dryer as soon as it’s done can help to minimize wrinkles. Bonus points if you can catch it while it’s still a little damp to help create a bit of steam when you iron.
After you wash and dry your fabric, there are a few things you’ll want to do before sewing with them.
- Trim the threads. Cut all of those pesky frayed threads off with scissors or a rotary cutter.
- Press the fabric. Iron out all the wrinkles to help with accuracy when you go to cut your fabric.
- Starch if desired. Washing fabric relaxes the fibers and it will no longer feel as crisp as it was before you threw it in the wash. Starch can help fabric resume its crispness and stabilize the threads for cutting and sewing.
Let us know if you have any questions about prewashing in the comments!