8 December 2021

How to Insert a Sleeve

How to insert a sleeve - Tilly and the Buttons

Attaching a set-in sleeve, also known as sewing a sleeve “on the round”, is when the two circles of the sleeve head and armhole are joined together after the underarm and side seam have been stitched. It’s a bit fiddlier than attaching them while the pieces are still flat but it allows you to create beautiful shaping at the shoulders on your me-made clothing. Seen here on a lovely polka dot Mathilde blouse.

How to insert a sleeve - Tilly and the Buttons

The reason we’re adding fullness at the shoulder is to help the fabric curve over your shoulder where it sticks out from your body. A sleeve head is often at least 2cm (3/4in) bigger than the armhole - on some sewing patterns it's even bigger to create more visible gathering as a design detail. This excess fabric is gathered in so the circumference of the sleeve head and armhole match when sewn together, creating volume in the fabric to accommodate your shoulder.

In case you’re interested, not all sleeves are inserted this way. Some sleeve heads don’t have any ease at all. An alternative method - often used in shirt-making and on jersey t-shirts - is to insert sleeves “on the flat”, in other words, stitched flat against the armhole before the bodice side seam and sleeve underarm sleeve are joined.

Anyway, that’s the theory over – let’s get on with the sewing!

In the tutorial below, Abi is sewing lovely set-in sleeves to a Martha dress

How to insert a sleeve - Tilly and the Buttons
While the sleeves are still flat, we're going to start by adding gather stitchers - or "ease stitches" if the sleeve is less gathered - on the head. Thread up your machine in a contrasting colour, set the stitch length to 4-5mm, and lower the thread tension - this will make it easier to identify, pull on and rip out these stitches later.

Stitch three rows parallel to each other on the top of each sleeve. Your pattern will have either gather markings or notches showing you where to start and finish the stitching. Sew your first row 5mm (1/4in) from the raw edge, and then each subsequent row 7mm (1/4in) from the previous one. That way they don't overlap the seam line 15mm (5/8in) from the edge, so they're easier to unpick later. 

Don't back tack, and leave a few inches of thread at each end so you have something to pull on when it comes to gathering.

How to insert a sleeve - Tilly and the Buttons

If you’re sewing a balloon style sleeve like the Mathilde blouse, it also has gathering where the sleeves meet the cuffs, so stitch three rows of gather stitches at the sleeve hem too, beginning and ending about 25mm (1in) from each side seam.

How to insert a sleeve - Tilly and the Buttons

Stitch the sleeve underarm seams, finish and press. 

Now we’re going to align the sleeve and armhole. The way to check you’re putting the correct sleeve into its corresponding armhole is to look at the little notches you cut from your pattern (if you don’t know what I’m talking about, check the pattern again). The front of the sleeve and armhole will have single notches; the back will have double notches.

How to insert a sleeve - Tilly and the Buttons

Align the sleeve and armhole, with the fabric right sides together. This can be a little confusing the first time you do it, but really all you need to do is hold the sleeve right sides out and turn the garment wrong side out on top of it so the right sides are matching. Then line up the two raw edges of the sleeve and armhole seams.

Pin the sleeve and armhole together - with the pins at right angles from the raw edge and the heads sticking out - at the following points:

- Where the sleeve underarm seam meets the bodice side seam
- Shoulder seam and central point on sleeve
- Sleeve and armhole notches (those single and double snips we were talking about earlier)
- Below the gather stitches (don't pin on top of the gather stitches just yet)

How to insert a sleeve - Tilly and the Buttons

Pull on the gather stitches – gently tug on a trio of threads on one side of the fabric only to bunch up the fabric. Keep doing this until the sleeve fits into the armhole up to the shoulder, smoothing out the gathering as you go to spread it nice and evenly. Repeat on the other side of the shoulder.

How to insert a sleeve - Tilly and the Buttons

Now stick as many pins in as you think you’ll need to help keep the gathers even. (Lots is good.)

If you’re super confident, or if the pattern you're making only has a bit of ease, you can go right ahead and stitch. If you're less confident, or if there are lots of gathers, it's a good idea to tack (baste) first though to check you’re happy with your gathering. Tacking basically means sewing a practice run with long stitches (4-5mm) which are easy to rip out if you want to try again. Thread up your machine in a contrasting colour so you can see the stitching easily and thus whip them out quickly. Lower the presser foot pressure slightly to avoid squishing the gathers. 

Tack just within the seam allowance - about 12mm (1/2in) from the edge - so your real stitches don’t end up directly on top. When stitching, start at the underarm seam. Sew nice and slowly over the gathers so you can keep them evenly in place as you go. Come full circle to meet your starting point, making a couple of overlapping stitches to secure. 

The aim is to end up with even easing or gathering, with no pleats or puckers. If you find any, you can unpick and re-stitch a short length of stitching around that area.

How to insert a sleeve - Tilly and the Buttons

Once you’re happy with your tacking, rethread your machine in matching thread to your fabric, reset the stitch length to normal (2.2 - 2.4mm) and sew your real stitches. Now you can unpick your tacking and gathering stitches with a seam ripper.

How to insert a sleeve - Tilly and the Buttons

All that’s left to do now is finish your seam with zigzag stitch or an overlocker, and press it. When pressing the armhole, turn the garment inside out and press along the seam. If you want to you can press the seam in towards the sleeve, but try not to press the shoulder area, otherwise you’ll lose the fullness you’ve created with your gathers.

How to insert a sleeve - Tilly and the Buttons

Admire your hard work. Hooray! You set in a sleeve!

If you liked this post check out Ten Tips For Sewing Gathers and How To Sew An Invisible Zip