27. Dear Gabby: The Great Shoulder Adjustment Digest—Part 1

This certainly can’t touch the idea of the Great American Novel, but if you’ve been looking for a place to learn how to identify common shoulder fit issues of all flavors, you’re in the right spot! (For part 1, that is!)

The shoulder is arguably the most fit critical area in garments made for the upper half of the body. Problems stemming from the shoulder affect overall garment balance, can cause draglines through the entire garment, and can cause great discomfort while wearing. So what’s important to know, you ask? Keep going, gentle reader, resources will be italicized throughout!

* A quick note- I reviewed all the resources linked for clarity and ease of instruction. There are simply gobs of knowledge out there, pattern books, videos and courses galore. Of course, the best way to learn how to fit is to take classes and practice, but barring that, I specifically looked for approachable, easy to follow instructions that will provide a good base and allow entrée into more specific and focused areas. (In other words, don’t scare off the newbies! ☺️)


The first thing to understand is the “slope” of a shoulder. Shoulder slope is, in essence, the measurement created by the angle that the trapezius muscle slopes downward, between your neck and your shoulder. For our purposes, imagine a pattern piece: the shoulder seam line is drawn starting at the side of a neck, follows the top of the shoulder, and ends at the armhole. The measurement between the highest shoulder point and the lowest shoulder point (measured vertically) is your shoulder slope. This is applicable to all ages and sexes and will not change based on who you are sewing for.

Image shows a dressform with an arrow indicating the downward slope of the shoulder, and a pattern with a shoulder slope placement indicated for how to take the measurement.
Image shows a dressform with an arrow indicating the downward slope of the shoulder, and a pattern with a shoulder slope placement indicated for how to take the measurement.

*Freesewing.org has an excellent explainer diagram and measuring method on shoulder slopes.)
*Below is a video from Threads that quite clearly illustrates shoulder slopes:

Threads: Shoulder Slope 101

Now that we’ve covered what a shoulder slope is, how can you measure this on yourself? There are a myriad of ways to do this:

  • Tape a piece of paper on the wall. Stand facing out, and have a partner trace your shoulder line from neck to arm. True this line, and measure the angle amount. Again, a video from Threads that has many helpful tips.
  • As freesewing.org recommends, take a selfie. The amount you need to rotate the photo to make your shoulder line horizontal is your shoulder slope measurement.
  • There are several smart phone apps that will measure angles, you may need a helper for these as well.
  • Of course, you can always use a pattern that fits well to check this measurement, depending on the neckline and armhole. Something very basic will work best for this.

Now that we have our shoulder slope measurement, you can use this to create a tool to help you check this on patterns, or simply keep this measurement in mind to measure patterns before sewing, so you can adjust before cutting into your fabric.

So, what happens with shoulder slopes? What would we need to adjust? Drumroll please… presenting the two most common problems that can happen with shoulder slope! Too much and not enough. Let’s explore.

I’ve created a mockup showing too much slope, just the right amount, and too little, by sewing a shoulder line in 1/2″ increments. The shoulder/armhole join point has been left the same throughout, only the slope has been changed. I also left the seam allowance and stitch line visible, and I want to point out especially the draglines. The first image shows too much slope:

Image is a muslin mockup on a dressform, one side with no notation, and the other noting the presence of a dragline that starts at the shoulder and releases at the neckline.  Shoulder seam does not sit along the shoulder, it stands up at the neck.
Image is a muslin mockup on a dressform, one side with no notation, and the other noting the presence of a dragline that starts at the shoulder and releases at the neckline. Shoulder seam does not sit along the shoulder, it stands up at the neck.

Do you see how there is a slight point at the shoulder/armhole join? And how it starts coning at the neck? That’s a hallmark of a Too Much Slope dragline. You can also see how the neckline is standing away at the neck/shoulder join.

Workroom Social has a very good visual of the unevaluated problem and how they’ve pinned out the excess to show the issue over on the old IG.

This next photo shows a shoulder slope with just the right angle- the mockup lays smoothly along the shoulder, with no gapping or draglines anywhere.

Image shows the same mockup, sewn with less of an angle at the shoulder seam. Mockup lays smoothly along the shoulder of the dressform.

This next photo shows not enough shoulder slope- the mockup itself is clinging at the neck/shoulder join, and there is a point formed along the neckline and the coning is releasing in the armhole area.

Image is a muslin mockup on a dressform, one side with no notation, and the other noting the presence of a dragline that starts at the neckline and releases at the armhole. Shoulder seam does not sit along the shoulder, it stands up at the armhole.
Image is a muslin mockup on a dressform, one side with no notation, and the other noting the presence of a dragline that starts at the neckline and releases at the armhole. Shoulder seam does not sit along the shoulder, it stands up at the armhole.

This next photo is the same slope—it’s still too square, and you can see how the point/coning is shifted down in to the body area. This is what people mean when they say “a dragline is pointing to the problem”—draglines are not actually a line, they’re fullness and folding, created when a point needs to be released at the very start of them. Look for the smallest point of a “dragline”, and there you shall see your problem area (the “pointing!”). Imagine, such a large “dragline” being created by a difference of only 1/2″ in slope. This is what I mean when I say shoulders are arguably the most fit critical on a top…

Image shows the same mockup on a dressform, but the dragline has been shifted so the coning releases at the hem.  The point of the dragline is still at the neckline/shoulder join.
Image shows the same mockup on a dressform, but the dragline has been shifted so the coning releases at the hem. The point of the dragline is still at the neckline/shoulder join.

Again, Workroom Social‘s visual of the problem and the pinning are great examples!

Additionally, I know that illustrations in pattern books or other resources can be highly confusing- often, they are just a bodice with some wiggly lines drawn on it, like so:

Image is an illustration that is supposed to show draglines on a bodice that will point out whether there is too much slope or too little, but the illustration is not very clear and it is hard to distinguish the difference.
Image is an illustration that is supposed to show draglines on a bodice that will point out whether there is too much slope or too little, but the illustration is not very clear and it is hard to distinguish the difference.

That tells me exactly nothing, unless I was the illustrator and thought those infinitesimally small variations were completely readable to someone who obviously was already familiar with what these slope issues look like. (Spoiler, I was, I drew this to illustrate my frustration with wiggly-line fit illustration guides).

And so—how to fix? You’ll need to adjust the angle of the shoulder line, by either reducing the angle at the neckline (don’t forget to drop your neckline accordingly, unless you like it to sit higher), or by dropping the angle of the shoulder line at the armhole (don’t forget to drop the armhole at the side seam accordingly, unless you want it to sit higher). Links below for visuals:

*Katrina Kay has an excellent video showing how to make these adjustments.
*And yet again, Threads to the rescue! I found this a little more complicated, but better if you like slashing and spreading, versus eyeballing and measuring.

These correction are not complicated, and I would make sure you have accurate measurements to ensure your sleeve still fits into your armhole, if you don’t have to make additional changes to your sleeve cap.

*And a quick note- it’s extremely common for the right and left shoulder slope to differ, based on how muscular one or the other sides can be. Your dominant side will typically have less of a slope and more muscle mass. This is totally normal, everyone has asymmetries in their figure!

We’ve now covered the basics of shoulder slopes, and that’s all I know about shoulders.

Just kidding! 🙃 Be on the lookout for further posts about on this subject, and keep in mind that fixing shoulders on a pattern means you also have to consider the neckline and the armholes. Yay! 😁


Gabby is a technical designer, fit specialist, and prolific googler. She lives in Denver, raises tiny littles, reads, embroiders, makes, experiments, fails, learns, tries again. See her on instagram @ladygrift.


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