Sewing a welt seam is a way of finishing a seam that needs to be strong and durable. Learning how to sew this effective and easy seam will impress you, and give you the confidence to share this technique with other eager sewers. The welt seam is similar to other seams, like the French seam, because it is a closed seam and is double stitched. However, it is stitched flat and this makes it ideal for the inside of jeans and skirts.
WHat is a Welt Seam?
A welt seam is a type of seam that has been sewn flat by first stitching on the wrong side and then securing it on the right side. The welt seam is ideal for use on heavier fabrics needing stronger seams and less bulk.
This useful seam is often called a mock flat felled seam. When it is finished it looks like a felled seam, but it has the advantage of not incurring too much bulk.
Welt Seam Vs Flat Felled Seam
Welt seams are close to being a flat-felled seam, but the difference is they are less work and quicker to finish. The welt seam is not enclosed like the flat felled seam, but it does create a neatened edge and with extra stitching, it flattens the seam creating a smoother finish. The neatening part can be done by your serger, if you have one, or with a simple zigzag stitch on your normal machine.
If the fabric you are working with frays easily, then it is a good idea to neaten the edge with a row of stitching or a zigzag before you start to work on the difficult edges of the fabric. You can stop unnecessary fraying with a row of straight stitches before you have a chance to finish the seam.
Purpose of a Welt Seam
Why would you use a welt seam? There are several reasons to choose this seam. Knowing how easy and useful it is may influence your decision in the future.
- It is an easier than it looks seam to sew.
- The welt seam is strong and hard-wearing.
- It finishes off the inside and the outside of different straight seams very neatly.
- When you need to reduce bulky seams and have a controlled neat look inside and out, then this is a good seam to choose.
- The welt seam can be decorative and practical at the same time.
- Variations of the welt seam add diversity to the garment you are making.
- The welt seam can actually look like a decorative tuck when the open welt is used.
- Welt seams have other purposes besides being a seam. These are described in the next paragraph.
How to Sew a Welt Seam
Here are four easy steps to take to sew a welt seam.
Step 1 - Sew the Seam
Stitch your plain seam together according to the pattern’s seam allowance. Set right sides together and stitch in a straight line.
Step 2 - Finish the Seam
Finish the raw edges together either with a zig-zag stitch or a serger. If you are using a serger, do not trim too much off.
Step 3 - Press
Press the seam to one side.
Step 4 - Topstitch
Topstitch the seam edge down on the same side as the folded seam allowance to secure the sides of the seam that has been neatened. Use a presser cloth to press the seam flat.
Open Welt Seams
A welt seam is particularly useful for neatening thicker fabrics or fabrics that fray easily. It is a quick, but secure method of neatening a seam. Another version of the welt seam is an open welt seam. The open welt seam is a decorative seam and resembles a tuck. It is an easy-to-do seam and useful on a stitched yolk, giving a tucked effect.
Follow these steps to sew an open welt seam:
Put your fabric right sides together and sew a row of basting stitches (L4.0) along the stitching line. Leave a tail end to the basting at each end of the seam. The tail end is important because it will enable you to pull out the stitches at the end. Do not put a knot or double stitch to secure your basting because it has to pull out easily.
Finish off the seam allowance in your chosen method and press the seam allowance to one side.
Now on the right side, stitch a row of topstitching ¼ inch (6mm) away from the original basting of the seam. This stitching must be on the same side as the side you folded the seam allowance.
Press your seam flat.
Remove the temporary stitches by pulling the basting threads out of the fabric. The threads should pull out easily as you use the tail ends to bring the basting through to the other side and dispose of them. Using a different color thread will make sure you have removed all the basting stitches. If the stitches don't pull through, use a seam ripper to gently remove them.
The seam will appear to open. However, it is not an opening it is a tuck created by the stitching after the neatening and pressing is complete.
This tuck has several decorative uses on the edges of a yolk or to create detail on a cuffed seam. The open welt seam has been used to hold piping in upholstery and to fit boning into corsets and other fitted garments. There is more to this seam than meets the eye!
Double Welt Seams
Then there is the double welt seam. The double welt seam is the same as a welt seam, but an added row of stitching makes this seam stronger and gives it a decorative finish. The double welt seam helps to control bulky seams and keeps the single welt edge from popping up when you need it to stay flat.
Using contrasting colors for the stitching of the double welt seam to add a decorative feel to the seam.
From the outside, the double welt seam looks like a run and fell seam or a flat felled seam. However, because it is not folded over it does not have the bulk of the run and fell seam.
Welt Seams and Corsets
Did you know that the welt seam is a great way to make the partitioning for the boning of a corset? This is probably not something you would rush out to make, but you never know when you may want to add boning to an outfit or to a traditional costume or dance dress. If you do decide to make a corset then a welt seam is the best choice to make the seam pocket, or casing, to slip the spiral steel boning into.
Boning is also a way to add shape to swimsuits and strapless bodices. The boning will add structure to many garments and the welt seam is a perfect seam to provide the support and casing for the boning. The other advantage of using a welt seam for this purpose is if you decide the boning does not suit your style or becomes uncomfortable, it is easy to slide the boning out, and then you are left with the welt seam. This is still a very neat way to finish your seam and complete the corset.
Welt Seams - In Conclusion
The welt seam is probably one of the underestimated seams. It has the advantage of looking good on the outside where you want the lines and finishes of your garment to stand out. Then, on the inside, it is finished off quickly with a practical approach that strengthens and neatens the seam. When you use the welt seam be aware of its advantages, it has strength and it is a speedy seam to whizz up. The welt seam is really great for the rough and tough projects using the thicker fabrics like denim, but it is a seam you may want to test drive before going all out and using it for every seam.
To welt or not to welt may be the question. The best advice is to try this seam and see what you think suits your garment, your fabric and your time frame the best. It really is a quick means to an end and worth adding to your repertoire of quick and easy seams.