When should you use a French seam?
French seams are perfect for use on lightweight or sheer fabrics, encasing all of the fraying fabric edges inside a tiny seam allowance of 1/4″ (5mm). French seams can be fabulous to use if you haven’t got an overlocker (serger) and want to create a perfect finish to your garment.
French seams work best on light to medium weight fabrics, as heavier fabrics can produce bulky seams. Although they can be used around the arms eye to great effect they don’t work as well on curved or shaped seams.
This tutorial shows how to create a French seam with a 5/8″ (1.5cm) seam allowance. If you have a different seam allowance you will to amend your seam allowance to 5/8″ (1.5cm).
Watch our corresponding YouTube tutorial: How To: Sewing French Seam.
Let’s get started!
Start by pinning your fabric WRONG sides together (I am working with a printed fabric so you can clearly see the wrong and right side of the fabric). Pin along the edge you wish to sew.
Sew 3/8″ (1cm) away from the seam allowance on the sewing machine. I am working with a alternate thread colour to make it easier to see.
Press the seam flat to meld the stitches into the seam. Press the seam open.
Trim the seam allowances to 1/8″ (3mm). The seam allowances MUST be trimmed to 1/8″ (3mm), as next we will sew a 1/4″ (5mm) seam. If the seam allowances are not trimmed small enough, they will protrude through the final seam.
Place the fabric RIGHT sides together and press flat so that the previous stitching line is located along the edge of the fabric. Pin in position if required.
Sew 1/4″ (5mm) away from the previously stitched seam (now the folded edge).
Press flat to meld the stitches into the fabric and then press the seam allowance towards the BACK of the garment.
Congratulations you have sewn a French seam. We would love to see what you’ve been making with this tutorial. Feel free to share your work on Facebook and Instagram.
French seams are ideal for lightweight and sheer fabrics, as they fully enclose the raw fabric edges inside a very narrow seam allowance. This creates a clean, durable finish on the inside of a garment — perfect when the fabric is prone to fraying.
French seams are also a great option if you don’t own an overlocker (serger) but still want a professional internal finish.
They work best on light to medium-weight fabrics. Heavier fabrics can create bulky seams, which is why French seams are not recommended for thick or structured materials. While they can be used successfully around the armhole, they are less suitable for highly curved or shaped seams.
This tutorial demonstrates how to sew a French seam using a 5/8” (1.5 cm) seam allowance. If your pattern uses a different seam allowance, you will need to adjust it to 5/8” (1.5 cm) before beginning.
You can also watch the corresponding video tutorial on YouTube:
How To: Sewing a French Seam
Begin by placing your fabric wrong sides together. I’m working with a printed fabric so the right and wrong sides are easy to see. Pin along the seam you wish to sew.
Sew 3/8” (1 cm) from the raw edge. I’m using a contrasting thread colour here to make the stitching easier to see.
Press the seam flat to meld the stitches into the fabric, then press the seam open.
Trim both seam allowances down to 1/8” (3 mm).
This step is essential — the seam allowance must be trimmed small enough so it doesn’t show through the final seam. The next seam will be sewn at 1/4” (5 mm), so accuracy here matters.
Place the fabric right sides together, folding along the previous stitching line so it sits exactly on the edge of the fabric. Press flat and pin if needed.
Sew 1/4” (5 mm) from the folded edge, encasing the trimmed seam allowance inside.
Press the seam flat to set the stitches, then press the seam allowance towards the back of the garment.
Congratulations — you’ve sewn a French seam 🎉
A beautifully neat, enclosed finish that’s perfect for delicate fabrics.
We’d love to see what you’ve been making using this tutorial. Feel free to share your work with us on Facebook or Instagram.
