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Gaping Arm Scye

How to fix a Gaping Arm Scye

Hey it’s Noreen chatting with you about fitting again!

Raise your hand if you’ve ever had an issue with gaping around the armhole.  Lot’s of hands, mine included! I’m going to use the Presto Tunic  which is today’s Feature Friday pattern to talk about that gap that we often see in our front armhole or armscye. 

Side Note: A few of my other fitting posts were about adjusting a bust dart and sewing a round back adjustment. Looking for more sewing basics? Check out my sewing a v-neckline video and my sleeve sewing tutorial.

The Pattern

Today’s Feature Friday pattern is Presto Tunic. This versatile pattern has just been given a sizing update and with all the options for both sleeves and sleeveless tops it’s the perfect choice to work on our fitting!

Get the pattern here
Inset piece with button placket
Vented chunky hem line
Choose from standup collar or bias bound collar.
optional back darts
Sleeveless, short sleeves, 3/4 sleeves, or long sleeves.
optional waist tie


Let’s understand the problem

A few important things to note first before we get started.  If you are putting sleeves in your garment, you do need some gap or ease so that you can move your arms.  The gapping I’m addressing here is for when we are making sleeveless garments.  Often, when we experience a gap or too much fabric in the armhole the first thought is that we may need more room in the bust and that may be partially true but I don’t think that assumption is the first or even best place to start our investigation.  We need to start with our measurements and choose the correct pattern size or sizes as the case often is.  It is so important to start with your high bust measurement not your full bust and blend out if necessary to your full bust size. If the armholes on your garments are gapping it could be as simple as the fact that your garment is just plain too big in the entire upper chest and sizing down will take care of the issue. Here’s what can happen if we pick our size by just our full bust measurement. We can see from my muslin that I have all kinds of issues but instead of doing a bunch of different pattern alterations, many of these can be addressed by just sizing down in the upper bust and blending out to the next size at the full bust.

And bust dart is too high.

Do you need this adjustment?

If you struggle with this issue, the problem could originate from several places – so it may not be that straightforward.  Since our bodies are so unique and different even though we are in the correct size, we may still have a gap.   If that is the case for you we will have to put on our detective hats and work through a few steps to see what we need to do. Assuming that we are in the correct size, here are the


 Other factors that contribute to gaping:
  1.  Correct bust placement
  2.  Shoulder slope 
  3.  A shorter shoulder to bust apex length than the pattern 
  4. More shaping or room in the bust

Even though I’m  going to be working these alterations on the Presto Tunic, these methods will apply to any pattern. So grab an old sheet (my favorite for working through muslins) or some fabric, your pattern and let’s dig in!

How to Fix a Gaping Arm Scye

Step One: Check your Dart Placement

With your muslin on first check your bust placement.  Most often we want to work our fitting from the top down and since everything hangs from the shoulder it’s usually the first thing to adjust but if you need to move your dart, whether up or down, do this first. Getting the bust in the right spot is critical to how our garments fit!  I wrote all about darts, bust apexes and how to move darts and you can find that post here.

Now that the size is correct and our bust darts are fitting our body correctly let’s try on our muslin again and assess that gap.  It’s quite possible that it’s now gone!  

Step Two: Investigate the Shoulder Slope

If there is still some gap it’s time to  pull up on just the outside of  your shoulder seam. Does that eliminate or at least lessen the gap?   That would indicate that your shoulder has a bit deeper slope than the pattern.  

To do this adjustment mark the amount you pinched out on  the outside of the shoulder on your pattern and draw a straight line to the edge at the neck.  To do this on the Presto, you will need to lay the bodice yoke over the front to complete the full shoulder.  

Step  Three: Adjust the Arm Scye

If that is not the problem  then maybe the armscye is drafted longer than you need for your body.  There are two ways to address this. 


METHOD ONE – Cut and Overlap

If you have pooling across the entire upper chest then you can cut the pattern from center front through the armscye above the notch and overlap the whole bodice the amount you need to shorten it. 


Otherwise, pinch out the amount you need to remove the gap. 


As you’ve worked through this process you still might be thinking that you just need more room in the bust but hang in there with me because doing this alteration will open up your dart a bit!  For me it was just the amount I needed.  

To shorten your armscye


  1. Draw a line through your dart to the apex and another line from around the notch on the armscye to the apex
  2. Mark the amount you need to remove on either side of the line you drew.  For example if you need to shorten it ½” then mark ¼” on each side.  
  3. Cut to but not through the apex on both the first lines you drew.
  4. Now you can pivot at the apex and overlap the armscye lining up the marking and removing the excess length.  And look!  You’ve opened up the dart a bit!  
  5. Lastly, true the armscye and redraw the dart.  


I’d like to note here that if you have a bit of a fuller cup size you do have the option to turn that overlap into a dart instead of simply overlapping it.  This can  add some nice shaping to the bust!

Let's Double Check

Whew!  That seems like a lot but let’s check our list: 

Correct size – Check!

Bust alignment – Check! 

Shoulder slope – Check! 

Shorten the armscye- Check! 


Whichever adjustment you need or which combinations you used you should have a pretty great  fit! And now, finally you can decide if you need a bigger FBA.  Remember we need some ease in our arms if we are putting in sleeves so that we can move so if you’re adding sleeves don’t take out all the gap!   

Can’t wait to see your adjusted Arm Scyes

“Oh My Word!” was my exact quote when I sewed up my final Presto after the changes I made!  This pattern is super versatile and  with all the different fabric choices and design options you can make it for all seasons and occasions.  I particularly love the longer back and the side split.  And the bodice yoke, placket and collar.  I mean what a great place to add some fun details!  My favorite was using a contrasting fabric for the placket and collar. 


Thanks for joining me on another  fitting journey today.  I hope these tips help you embrace your wonderful unique self and to encourage you to  persevere in your sewing journey because you deserve to have great fitting clothes too!

Shop Presto Here

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Author Tessa

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