Adjustments for One and Two Piece Sleeves

With the expansion of our size range with the Sienna Maker Jacket we have been talking a lot about fit around here. As the tester feedback rolled in we began to notice that one of the most common areas of adjustment was in the shoulder/ sleeve/ armscye region. We ended up making quite a few tweaks for the final product but as with all fitting issues what works for most people, won't work for ALL people. This is where we have to remind ourselves as pattern drafters and sewists that the whole reason we got into this game was to make garments that fit us, not the other way around! So in the spirit of DIY we are giving you another blog post from Celine our master pattern drafter so that she can show you how you can easily adjust any one or two piece sleeve to fit you exactly how you want it; be that smaller or bigger. Take it away Celine!

Depending of the size and shape of your arms, your shoulder slope etc. you might find that your sleeves are too tight, too baggy or just don’t fall as well as you wish they would! As a general rule, sleeves should have 1-2” of ease through the bicep depending on the fit of the garment. A slim fitting shirt may have an 1” of ease through the bicep (which you can test by pinching fabric at your bicep during the muslin stage), but a looser fitting garment like our Sienna Maker Jacket should have 1.5-2” of ease through the bicep for maximum comfort.

Sleeves are the trickiest part to adjust on the body as it often means you will have to make changes to the bodice of a garment as well. Here are the quickest ways to reshape your sleeves, to add or remove some ease at bicep, making as few adjustments as possible to Front and Back.

Adding a small amount of ease for full bicep adjustment with two piece sleeve:

If your sleeve is a bit too tight on the upper part of your arm, you’ll need to slash and open the sleeve at the bicep to add some fullness.

For a two-piece sleeve, overlap top sleeve and under sleeve so that seams are on top of each other at upper part of the sleeve, as shown. Draw the bicep line perpendicular to the top sleeve grainline. Trace a line at center of sleeve cap down to hem. Your bicep adjustments will only be on the top sleeve piece. Cut through seam line to stitch line (to the dot in the drawing) and cut along lines inside the pattern piece to the seam line. The seamline will then still be intact and won’t change in length even when rotating the pieces (this is important since it needs to match the under sleeve!)

Open your sleeve (spread between arrows) at bicep, each side an equal amount to center line. You can open up to 1” so that the sleeve cap shape won’t change too much (when opening the sleeve, the sleeve head gets flatter which can alter the overall fit). Anchor the sleeve by taping the overlapping pieces. You can then tape your slashed sleeve to a piece of paper and retrace and true all lines and seams. Trace your bicep line and new grain line and voila!! You’ve just added an inch of bicep ease to your sleeve.

Adding a larger amount of ease for full bicep adjustment with two piece sleeve: 

If the sleeve is really tight and still restricts movement, the amount added at the bicep needs to be larger. As a result, the sleeve cap will be reshaped as well as the bodice armhole.

First, trace your sleeve cap as is on a separate piece of paper. (For a two piece sleeve, you’ll repeat the same steps as the previous section, but will add more than 1” of ease.) Slash and open amount you need. You can see your sleeve head has been flattened quite a lot. Tape your slashed sleeve to your reference sleeve cap and blend your lines to draw your new sleeve cap as shown. Retrace and true all lines and seams. Trace your bicep line and new grainline.

Your sleeve head seamline measurement is now larger. To avoid having to ease in more sleeve cap length to your armscye,  you’ll have to adjust the Front and Back armhole to match the new length. You can either extend the armscye seam line the needed amount, or lower the armscye curve, depending on the desired fit (lowering the curve will give you a deeper arm opening, and may reduce mobility through the arm slightly).

Full bicep adjustment for one piece sleeve:

To make a full bicep adjustment for a one piece sleeve, simply follow the same steps as directed above. If you’ve added less than 1”, reshape the sleeve head by truing the curve. If you’re adding more than 1”, you’ll have to retrace the seam head and reshape Front and back armhole.

Small bicep adjustment/ How to slim a sleeve:

If your sleeve is too loose at the bicep and sleeve head, you can use the same method as above to remove width.

Overlap rather than slashing the pieces as shown to remove volume. I suggest tracing the original sleeve cap so you can retrace it once the alteration is done, since removing volume in this way will raise the sleeve cap which isn’t necessarily what you want.

Making the sleeve and armhole bigger for comfort:

Another common fitting sleeve issue is an uncomfortable fit due to movement restriction at the underarm. If your sleeve is fitting properly at the shoulder and bicep but still feels tight in the underarm and at the torso, you can add some ease for comfort.

For a two piece sleeve, the adjustment will be made on under sleeve only. Trace your bicep line as shown before, overlapping top sleeve and under sleeve seamlines. Trace a line perpendicular to bicep line, from notch to hem. Slash and open piece at bicep, equal amounts on each side to center line. Retrace the seamline and seam allowance, keeping notch on the center line. The amount added on each side of the notch should be added to Front and back bodice, lengthening the underarm seam and blending in side seam, just like we did for a large bicep adjustment.

For a one piece sleeve, the adjustment will be made on each side of the bicep. Extend your seamline the desired amount at  bicep level and blend in to hem of the sleeve. Retrace the seam allowance. The amount added on each side of the sleeve should be added to Front and back bodice, lengthening the underarm seam and blending into the side seam. 

So that's it! Now that you have all the tools you need, go forth and make all your sleeve dreams come true!