Seam construction can make or break a sewing project. We want to make sure your creations last a lifetime, so we’re kicking off a 2-part Sewing 101 all about seams. First we will go over basic seams for woven fabrics, and in the second installment we will cover all things knits!
The most basic of all seams, a plain seam is simply a straight stitch joining multiple pieces of fabric. Your fabric and project will determine the needle, stitch length, and tension setting on the sewing machine. For this example, we used Red Cotton Twill fabric.
You can use Universal (Regular Point) needles for woven fabrics. Their sharp point penetrates the fabric as it sews. Here’s a quick needle guide for size:
Very Lightweight or Sheer Wovens: 70/09
Lightweight Wovens: 80/11
Medium Weight Wovens: 90/14
Heavyweight Wovens: 100/16
Very Heavyweight Wovens: 100/18
Upon creating a plain seam, most likely a seam finish is required. A seam finish secures the seam allowance fabric so that it doesn’t fray or unravel.
Tip: You could choose to finish the edges before sewing the fabrics together, or after the seam is created. For beginner apparel sewing, we recommend finishing the edges prior to sewing a plain seam. For removable pillow covers, finishing the edges prior to sewing is easier because many home décor fabrics are easily frayed. Mostly, seam finishing in home décor sewing is not required at all since the fabric edge will never be disturbed or seen, such as upholstery sewing.
Zig Zag Seam Finish
The Zig Zag seam finish can be done on a standard machine. Zig zag stitch each seam allowance piece (or both joined together) and trim any excess fabric. Tip: When trimming, avoid cutting the zig zag stitching.
Overedge Zig Zag Seam Finish
This method cannot be used on very lightweight fabric, because it requires the right points of the zig zag stitch to go outside of the fabric. This is a very effective finishing method if a serger cannot be used.
Overedge Stitch on a Serger
This stitch can be done with or without the straight stitch (or chain stitch) depending on what kind of serger it is. A 5-thread serger can sew a plain seam, trim any excess, and finish the seam edge all in one step. These machines can be quite an investment, but it can save lots of time and give professional results from home.
Stitch and Pink Seam Finish
A classic seam finish, simply straight stitch each seam allowance piece, then trim the excess with pinking shears or a pinking rotary blade. A pinked edge will not unravel, but may fray slightly over time.
Time saving tip: depending on the project, you could skip the additional straight stitch step, and just trim the excess seam allowance fabric with pinking shears.
Flat Felled Seam
The flat felled seam is an ultra-secure, flat, and somewhat decorative seam most commonly used in jeans and pants construction. A combination of 2 visible stitches, this seam is fully enclosed.
Sew wrong sides together 5/8” seam allowance.
Trim one side to 1/8”.
Fold remaining 5/8” side under and over the trimmed 1/8” side, and top stitch.
French seams are ideal for delicate, sheer, or very lightweight fabric such as chiffon or crepe. A combination of 2 stitches, this seam is fully enclosed.
Sew wrong sides together 3/8”.
Trim seam allowance to 1/8”.
Turn fabric right sides together making the seam along the fold, press if needed, and sew ¼” seam allowance.
We will see you next time for part 2 of seam basics on knit fabrics.