Welt Seam Method Strength Layer with Floating Lining

What is a welt seam method? What does “Strength Layer with Floating Lining” even mean?!

We’ll start from the very start by defining a welt seam. Basically it is a straight stitch that had both seam allowances ironed to one side. That is followed by two parallel lines of top stitching to secure the seam allowances down. This seam type is a fairly popular option in corset making. It is so popular there are at least 4 different variations¬† used for corset construction.

Great part about welt seams is how easy they are to make.They are also good option to use as boning channels since seam allowances are made from the same strength fabric as the rest of the corset. This makes a sturdy “shell” for our boning, so it doesn’t pop out, without you doing anything extra to reap the benefits.
All of this makes welt seam methods perfect for beginners!

You’ll find in this tutorial how to sew the most basic and the easiest corset construction welt seam method works. These welt seams are to be used on the strength layer of the corset.

Seam allowance widths depend on the fabric thickens, number of layers as well as boning width and thickness. As always, making samples before starting your work on the corset, is always encouraged.

Tutorial sample is made using 200g cotton calico and 5mm wide spiral steel boning.

Happy sewing!

Free corset patterns

Aside from the instructional tutorial being available online, it can also be DOWNLOADED as a PDF file for offline viewing.

two pieces of fabric stitched together

Start by laying your pattern pieces right side on right side (or face on face).

Stitch them together with a plain straight stitch.

Seam allowances ironed to the side

With pieces connected, iron both seam allowance to one side. Either from center front to the center back or the other way around.

Pick one and stick with it. It doesn’t matter which one you pick, you just need to be consistent through out the corset.

Make sure you iron the seam allowances well. You don’t want crooked or creased boning channels on your corset.

Top stich close to edge

Stitch a straight topstitch line close to the edge of the connecting seam. This will lock down the seam allowances in place.

We need this line of stitching to remove some of the force from the connecting seam right next to it.

You measure the boning channel width from this line. Not the connecting seam!

Look at the seam allowances from the inside

Seam allowances are now held in place so your ironing doesn’t undo itself.

Notice that the seam allowances are rather bulky at the moment.
Depending on the fabric thickens, this can easily result in the allowance edge showing, through the layers, on the face of the corset.

Grading the seam allowances before closing the welt seam

You need to grade seam allowances to prevent or minimize the edge of allowance from showing on the outside of the corset.

Grading of seam allowances is very simple. You just need to shorten the seam allowances the top allowance and the fabric piece.

With just one seam allowance in between, simply cut its width in half.

Second top stitch paralel to the first one to create a boning channel

Sew another straight topstitch line parallel to the first one.

Distance between the two topstitch lines is your boning channel width.

Second stitch line also locks down the seam allowances further.

Raw seam allowances that need to be covered with a loose lining

Your distance between the second top-stitch line and the edge of the seam allowance shouldn’t be larger than 5mm or 1/4″.
Trim it shorter if it is.

Since this seam/boning channel construction ends with unfinished fabric edges, the corset needs to be lined with an additional layer of fabric to close it up and protect the fabric edges from fraying with regular wear.

Check out the “How to Make a Floating Corset Lining” by Sidney Eillen to find out for to make and add a floating lining to your corset.

Finished welt seam corset construction with a bone in the channel

You know you did it right if stich lines are straight, fabric is smooth and if the boning channel isn’t to tight or too lose your your steel.

Now go make some corsets!
Happy sewing!