How to Sew a Set-in a Sleeve

Sally Gauntlett explains how to sew set in a sleeve

Setting in a sleeve can feel daunting the first time you try but there’s no denying the fact that it’s a pretty useful sewing skill to have since most garments will have – well, sleeves! In this learn-to-sew post, I’m going to break down the steps needed to get the perfect set-in sleeve finish. Not a pucker or an accidental crease in sight!

Cutting out your sleeve pattern pieces

Let’s have a closer look at your sleeve pattern piece. Most sleeves will look similar to those in the picture below and will include two side seams, a straight or slightly curved hemline and a curved or domed sleeve ‘cap’.

Your sleeve pattern piece will include some very important notches which you’ll need to cut or mark into your fabric during the cutting-out process. The front of the sleeve is usually marked with a single notch, along with the centre notch at the top of the dome and the back of the sleeve is usually marked with a double notch. These notches will correspond with the notches in the armhole pattern piece of your garment and will help us to ease the dome of the sleeve into the armhole later.

Note: It’s always important to make sure you have a pair of sleeves cut that are mirror images of each other, so if you’re cutting your sleeve from a single layer of fabric, make sure that you flip your pattern piece over when you cut one of the sleeves so that you have a pair.

Let’s get sewing!

1. First, run some gathering stitches between the notches marked on our sleeve cap – these will help us to ease that large curve into the armhole. To sew a gathering stitch, set your sewing machine to its longest stitch length and, leave long thread tales from your machine and the bobbin. Sew two rows of gathering stitches between your notches. Be sure to leave long thread tails at the end of your stitching rows too. We’ll need to pull these up later.

TIP: Your pattern will often tell you how much of a seam allowance to take for each row of stitches, but a rough guide is to sew a few millimetres shorter and longer than your ‘normal’ seam allowance.

2. With your fabric right sides together, pin your underarm seam and sew at your sewing pattern’s recommended seam allowance. Finish the seam allowances either open or together with a zig-zag stitch on your sewing machine or with an overlocker. Press the seams open or towards the back.

3. I like to hem my sleeves at this stage before setting them in. This can feel much easier than doing it once they’re attached to the garment as you have more control. Hem your sleeve according to pattern instructions sewing with a nice, even straight stitch.

TIP: If your sewing machine allows, it can be helpful to remove the storage section of the machine and slide the sleeve over the arm. This will allow you to sew in one continuous round.

4. Next we will fit the sleeve cap into the armhole of the garment using the gathering stitches we sewed earlier. With your sleeve right side out and garment wrong side out (your fabric will be right sides together), slip the sleeve into the armhole and match up the underarm seam with the side seam of your garment. Pin in place and match up the centre notch on your sleeve cap with the shoulder seam of your garment and pin that in place.

You can now go ahead and match up your notches on the garment armhole and the sleeve and pin those in place. You should be matching a single notch with a single and a double notch with a double to make sure that your sleeve is facing the right way around.

Now evenly distribute the gathers around the curve of the armhole to allow the cap of the sleeve to sit nicely.  One side at a time, gently pull on the threads you left at the end of your gathering stitches and wrap the ends of the threads around the pin you placed at your notch in a figure-of-eight style. Carefully spread out your gathers from notch to centre until they are even. Pin liberally to keep everything nicely in place. Repeat this on the other side, notch to centre.

TIP: Some sleeve patterns will sit flat into the armhole with no gathers remaining and some will have some gathering in them to give the sleeve a little height and shape when it is worn. The sleeve in my photos has a gathered cap at the shoulder for decoration.

5. Sew your sleeve into your armhole with the required seam allowance, starting at the under-arm seam and sewing right around the armhole. Sew with the sleeve side facing upwards as this will help you see what you’re doing.

Sew slowly and carefully ensuring that you’re sewing between your gathering rows and not over them and that you aren’t allowing the fabric to pucker or crease.

TIP: Use a pin to help ease the gathers under the sewing machine foot if your sleeve has gathered. This will help them not to pucker. 

6. Before removing your gathering stitches, check that you don’t have any puckers or accidental pleating on the back and front of the sleeve. Turn your sleeve through to the right side and check that it looks as it should.

Once you’re happy, you can pull out the gathering stitches and finish your seam allowances together with a zig-zag or overlocker. Press the seam allowances towards the sleeve using the tip of the iron to set the gathers into place if necessary.

TIP: Using a tailor’s ham or a sleeve board can help with this if you have one, but it isn’t essential.

And there we have it, you’ve set in a sleeve! I really hope it wasn’t as scary as you thought it might be.

Thank you for reading and happy sewing!

Sally x

Author: Sally Gauntlett
IG: @secret_life_of_a_seamstress