WHAT IS IT?
A French seam is a narrow, fully enclosed seam. In France, it’s called an English seam! The seam is sewn with the right sides out first, then turned to the inside and sewn, enclosing the seam allowances within the seam. The result is tidy and clean without requiring a lot of work to finish the seams.
WHEN DO YOU USE IT?
French seams are perfect for sheer fabric, fabrics that fray or anywhere you want a clean finish. It’s best on straight seams or nearly straight seams. French seams can be done on curved seams but need clipping for them to lie flat, which may not be best for sheer fabrics or fabrics that fray easily. French seams are tidy and professional. Plus, there’s no need to worry about matching your serger thread! If you plan to use French seams, you need to decide before sewing any of the garment seams, as they are sewn differently starting from the first step.
Tips + Notes
Trim evenly, especially if your fabric is sheer. You’ll be able to see the trimmed edge enclosed in the French seam, so make sure it looks tidy!
HOW TO SEW A FRENCH SEAM
Make a tiny snip in both pieces at the top edge of the seam, indicating your seam allowance. My snip is 5⁄8″ (1.5cm) away from the raw edges. This will help you sew the final seam accurately.
Pin your fabric pieces together along the seam line, wrong sides together. The right side of your fabric is facing you. This is going to feel wrong, but it will result in a lovely finished edge. Trust me! Pin the whole seam line from top to bottom.
Sew the seam with a ¼” (6mm) seam allowance. Backstitch at both ends. Trim seam allowance to 1⁄8″ (3mm), or if it’s easier to think of it this way, trim the seam allowance in half.
Press your tiny seam allowance to one side. To make sure you didn’t press any ridges into your seam, turn the seam over and press the other side, too. Make sure the seam allowance is pressed as flat as it can be. You may find it easier to press the seam allowance first, and then trim it in half. It’s up to you!
Pinch your seam allowance along the fold, as shown. The seam line should be at the exact center of your fold, not rolling to one side or the other. Press this fold flat, rolling it out as you go.
Stitch ¼” (6mm) from the fold, using the clipped notch at the top of the seam to ensure you’re taking the proper seam allowance.
Your French seam is done! Press this seam toward the back or as directed in your pattern instructions.
Source : The Sewtionary An A to Z Guide to 101 Sewing Techniques + Definitions
About the Author : Tasia ST. Germaine