So Fresh and So Clean: Why You Need to Prewash Your Fabric Before Sewing

Always prewash your fabric before sewing; it’s one of the cardinal rules of sewing that appears in most beginner sewing tutorials and articles. But how often do you really follow this rule? And what fabrics are exceptions to the rule? Why do we have to prewash fabric in the first place?

If you’re new to sewing and have found yourself asking how much of a difference prewashing really makes, you’re in the right place. We’re here to break down why you should prewash your fabric, what fabrics can skip the washing machine, and if this same rule applies to quilters. Plus, we’ll also cover some potential issues that can arise from prewashing, so that you don’t have to worry about troubleshooting your sewing woes in the middle of a project. Save yourself some stress on your next trip to the fabric store with this quick read.

Why Do We Prewash Fabric?

In a word, shrinkage. Some fabrics, such as linen or cotton, tend to shrink when washed, especially for the first time they’re washed. This amount of shrinkage can be minimal up to a few inches, meaning it can affect the fit of the finished garment. If you’re worried about shrinkage with your sewing projects, it’s recommended to wash a test swatch of fabric. Also consider how you will launder your finished projects. Will your cotton tee be tossed in the wash on a regular cycle? It might be best to prewash your fabric on a similar cycle to see how it reacts.

Some sewists also prefer to prewash their fabric to remove excess chemicals and dyes, as it can prevent the dye from bleeding onto other garments. According to Amari for Cottoneer Fabrics, in their article “To Prewash or Not to Prewash”, “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.” Prewashing eliminates some of these chemicals and helps remove some of the stiffness from fabric after being on the bolt.

What Fabrics Should I Prewash?

It’s generally agreed that everyday fabrics such as cotton (including quilting cotton), rayon, linen, knit, and flannel often benefit from prewashing. Specialty fabrics like silk or wool can be dry-cleaned if you prefer. Do your research before prewashing your fabric, as different fabrics vary for the temperature of the water they can be washed in, whether they will easily fray (more on this in a minute), and whether they can be dried in a dryer.

Smaller pieces of fabric do not have to be prewashed, such as small precuts or fabric scraps. It is also recommended to stitch a zig zag stitch along the edge of your fabric if prewashing or to trim your fabric edges with pinking shears, as this will help prevent fraying. After prewashing, be sure to iron out any wrinkles in your fabric and to trim loose threads.

I’m a Quilter. Do I Need to Prewash My Fabric?

While garment sewing typically benefits from prewashed fabric (depending on fabric type), the opinions on quilters prewashing fabric are more mixed. Not prewashing quilting cotton can sometimes lead to crinkles in your quilt the first time it’s laundered. However, other quilters see the prewashing shrinkage as a potential hazard. According to April Giddings Cobb, in their article, “Let’s Talk About Pre Washing Fabric”, one potential issue is too much shrinkage with precuts. In describing their experience with prewashing fabric for quilting: “I washed the fabric because I wanted to strictly follow the rules. Guess what! The fat quarters shrunk to the point that I wound up short of fabric to make the quilt as instructed.”

Quilters have more leeway in prewashing fabrics, and it generally falls into personal preference. Prewashing can remove excess fabric dye and chemicals, but it can also fade your fabric and make prints and colors less vibrant. Prewashing also adds extra time into your projects, so if you’re on a tight schedule to finish a quilt, it may not be in your best interest to prewash. Suzy Williams from Suzy Quilts notes in her article, “Should You Prewash Fabric Before Quilting?”, that “Whether or not you pre-wash or don’t pre-wash, it’s not a bad idea to throw a Color Catching sheet into the wash with your quilt – especially if your quilt includes saturated colors.”

At the end of the day, prewashing fabric depends on the type of project you’re sewing, how it will be used and how often, and how much time you have. Garments benefit from prewashing, while quilts and home décor projects that will rarely be washed are less likely to require prewashing. We hope you’ve found our quick guide to prewashing helpful! Do you always prewash your fabric? Do you never prewash your fabric? Let us know below in the comments.