Fun with Fit part 5: fixing temporary discrepancies and fitting the armscye

Hi everyone and apologies for the lack of post last week, we have been busy fighting off a grotty cold in our house.

In this week’s fun with fit we are going to begin by addressing a couple of temporary issues that are the result of the slash and spread or slash and overlap approach we have taken with our fitting. Those of you who needed to widen or narrow your front bodices will have temporarily also added or removed width from your shoulder or neckline.  I will be demonstrating how we deal with the temporary and unwanted changes to these areas.

After this is will be showing you how I assess the fit of an armscye as I feel that this is really the only area of general fitting that Butterick  could be clearer on. I also firmly believe it is something that you absolutely need to get right for a comfortable fitting sleeve and garment in general. If your armscye is too low or too big it will have the effect of pinning your arms to your sides as your sleeve will be attached to your bodice too far away from your shoulder joint for ease of movement.

Lets get going then…

SHOULDER WIDTH: If you have widened your bodice front between bust point and side seam this will have affected the width of your shoulder. Shown on my calico toile below is a front shoulder which has been increased in width. I have marked this increase with an orange arrow.




If yours has increased or decreased in width it will no longer match your back shoulder. All we are going to do is to match our back and front shoulder seams up as normal at the neck and sew out from there ignoring the discrepancy at the other end. Below you can see the result of this on Miss Dressform.

Front and back shoulders joined with discrepancy in length at shoulder edge.

All we do from this point is simply draw in a smooth and correct line. The Butterick  block comes with three shoulder width guides anyway which I had you mark up in your toile in the last session so really our task has not changed as we would have needed to assess which one sat in the right place on our body and marked it on anyway. In the case of Miss Dressform her shoulders required the narrowest line so I simply marked this line on the back and carried it on through the front, sloping in at the correct angle for her shape and rejoining the original front armscye in a nice smooth line. You can see this below marked in bright green.



It is worth noting that you may not necessarily want to use any of the Butterick lines. You want your shoulder seam to end right at the edge of your shoulder before it starts sloping down into your arm. If yours doesn’t do this on one of the three Butterick lines simply mark your line in where it does.

You are less likely to have changed the width of your back shoulder during your alterations as we put any excess width from slashing and spreading into a larger shoulder dart and if the width was decreased by slashing and overlapping we simply eliminated the shoulder dart. However, if you have an incredibly narrow back and you reduced your back width enough to both eliminate the shoulder dart and reduced the width of your shoulder further then follow the above approach.

NECK WIDTH: Those of you who required extra room between bust point and bust point will have widened your bodice in such a way that your front neck will now be wider also. Below is a calico bodice front that has a temporary widened neck as marked with the orange arrow.



If this is the case simply sew up your toile as normal and pop it on. Be sure to accurately pin closed the opening we left on the centre front seam to enable you to get it over your head. I have actually put this opening in the back for the purposes of this demonstration but it is much easier to do this on your front when you are working on your own body as pinning together a back seam accurately is nigh-on impossible unless you happen to be proportioned like Mr Tickle and have a fully rotating head. Once you have your toile on look for signs that your neckline is too wide. Below you can see my toile on Miss Dressform demonstrating an ill-fitting baggy neckline.



This is a nice easy complaint to fix. We simply unpick our shoulder seam and smooth the excess fabric of our neckline area up towards our shoulder seam and pin our front and back together shoulders back together in a position that eliminates this excess. If your back shoulder seam was already positioned correctly (mid shoulder and level from neck point to shoulder point) then pin along your existing back shoulder seam which you marked up on your toile, only changing the position of your front shoulder seam to eliminate the neckline gaping. Below you can see my shoulder seam pinned from both the back and front view.

Shoulder seam pinned along original back shoulder seam line.

As you can see the position of the shoulder seam only changed on the front as pictured below:

New shoulder seam pinned and marked with green on front to eliminate neckline gaping

Be sure to mark you new front shoulder stitching line with a contrasting pen so it is easy to transfer back to your paper pattern.

This is a great time to assess your shoulder seam position more generally – if you also need to change the general position of you seam line so that it sits in the middle of your shoulder or at a different angle to accommodate a forward thrusting shoulder then do this at this point too, being careful to make sure you still correctly eliminate that extra neckline gaping. As with all general adjustments the instructions are included in your Butterick pattern so refer to those for great general shoulder fitting guidelines.

If you reduced the distance between bust point and bust point then you may find that your neckline is too tight. If this is the case simply follow the Butterick guidelines for addressing a tight fitting neckline. If you are very delicate across the bust and upper chest you may actually find that the slightly reduced neckline fits you fine so don’t rush in to correct it without assessing the fit first.


Once you have established that your shoulder seam and side seam are in the correct positions and that your bodice fits correctly across the front and back of your body you can fit your armscye. To do this you need to begin by clipping into you seam allowance up to your stitching line as I have photographed below:


Once you have clipped in this manner, temporarily tuck your seam allowance in as this will allow you to assess the fit without the distraction of those pesky seam allowances. Now the seam allowances are tucked in we can see that the armscye below is not a good fit at all.



You are looking for an arscye that sits about 2cm or 3/4 ” below your arm (represented by the top of the black tape in Miss Dressform’s case) and about the same out from your side to allow for arm movement once the sleeve is attached. It should follow the shape of your body in this area smoothly and there should be no obvious bagging at front or back. Do not be mistaken in thinking that a baggier armscye will result in more confortable clothes- it will limit your arm movement horribly once you have sleeves sewn into it! Equally well you don’t want it tight under the arm either. The armscye above is cut too low under the arm and is also bagging out in the back.

The first thing we will do to remedy this is to draw in the new underarm stitching line. In the case of my toile that is 5mm above the Butterick one. Yours may need to be lower or higher but follow this step either way remembering to mark using a different coloured pen so you know which is the new and correct line.




Next we need to address the gaping in the back of the armscye. In Miss Dressform’s case the gaping is happening in the lower half of the armscye so we are going to smooth this into the side back seam. If your gaping was happening in the upper half of the back armscye you would smooth it into the back shoulder seam. To do this simply unpick your side seam and  re-pin after smoothing the excess in this area. Your front side seam line will remain unchanged but the new back side seam line will need marking in. Below you can see that I have done this with green pen.




You won’t be changing the whole of the back bodice side seam- so your new line should slope out to meet the pre-existing side seam before the waist.

Follow the same approach if you have bagging in the front.

Once you have marked up your new perfect fitting armscye all the adjustments to our calico toile for this week are done. All that is left for you to do for this session is transfer all of these new adjustments back on to your paper pattern. At the same time you will obviously also want to transfer any other adjustments you have made following the Butterick instructions for fit. At this point I like to use a pen in a colour that I haven’t already used on my paper patter just like I did with the green pen on my calico in the photos above. That way I can recognise the new lines compared to the originals. I also like to make a brand new tracing once I have added all my markings, this saves having a paper pattern covered in too many confusing pen marks.

Next week I will be showing you how to fit your sleeves and how to turn your newly perfected fitting shell into a cardboard block!

Thanks for reading as always.



9 responses to “Fun with Fit part 5: fixing temporary discrepancies and fitting the armscye”

  1. Interesting! Thanks for a look into your design tuning process. I am always amazed at hoe ‘off’ commercial patterns are when I fit them onto my industry standard dress form. Just another reason to draft my own.

  2. I always struggle with fit in this area so thank you for such a detailed post! I do my best trying to make fitting adjustments myself, but there’s only so much I can do. I wish I had a personal fit coach with me in my sewing room to help out. …are you free this weekend? 😉 😉

  3. Such a fantastic tutorial – thank you! This is the simplest, most concise outline I’ve ever come across.

  4. Great tutorial here! You have a great way of explaining this concisely but clearly. Thanks for sharing this, can’t wait to see more!

  5. This is super helpful as I am having so much trouble getting the lower part of the armhole correct for my body. I am not sure what you mean in the following.

    “You are looking for an armscye that sits about 2cm or 3/4 ” below your arm (represented by the top of the black tape in Miss Dressform’s case) and about the same out from your side to allow for arm movement once the sleeve is attached. It should follow the shape of your body in this area smoothly and there should be no obvious bagging at front or back.”

    What exactly do you mean by “and about the same out from your side”?

    • Sorry cheryl, so what i mean here is around two cm down from where your arm begins and also about 2 cm away from the side of your body- so not flush against your skin as you need that space available if you are going to have a sleeve xx

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