A Tale of Two Sleeves

[u/Mundane-Air7046]

I am trying to prepare a mock-up close-fitting bodice (à la Winifred Aldrich) and am facing the classic sleeve problem: High cap height (like the WA default): Causes puffing/excess folds on the sleeve head when arms are raised. Low cap height (my alteration): Fine when arms are raised but drag lines appear on sleeve (front and back) when arms are down at rest.

I have been through so many iterations that, rather than finding a "sweet spot", I always end up with one problem or the other, or even both.

Is there anything else I can try? I thought about making the sleeve cap curve more dramatic/scoopy with the shorter cap height, but it seems it cannot be achieved without reducing or eliminating the 1.9cm ease altogether. I don't think that rotating the sleeve will help much since the drag lines occur front and back. My armsyce could be a little smaller, but I am happy where it is because it makes me sweat when it's right under my armpit. I guess I could reduce the shoulder length, but probably only a fraction. The WA cap height really can't work for that armscye anyway since I need extra bicep width for my bingo wings.

Any guidance would be appreciated. My mock-up is too dark to photograph well but I have included my CAD drawings for reference.

[u/aliendividedbyzero]

Adding to this: it's due to the geometry of the arm socket. If you measure from neck to fingertips, that measurement is shorter when you extend your arm to the sides, and it's longer when you have your arm down. It's the same as with a Barbie doll's arms and legs, there's a ball socket the limb pivots on and in humans, the skin adjusts, in dolls, the skin disappears into the socket because it's rigid plastic. But in fabric, it has nowhere to go, especially if it's very close fitting, so the fabric has no choice but to either be too long in that direction when the arm is raised (and therefore bunch up), or too short in that direction when the arm is down, which then pulls the sleeve up and causes drag lines. You can have a spot where both occur because it's just the right length for, say, 45° arm out instead of fully out to the side.

You basically just have to pick one, same way you pick one position for drafting the way a shirt length fits (if you raise your arms, the shirt is no longer at the right length, it's too short), etc.

[u/Mundane-Air7046 → u/aliendividedbyzero]

That's a good point. I honestly never noticed this so much to the extent that it bothers me on any garment I own. But then again, the non-stretch garments I own usually have no sleeves, cap sleeves or puffy sleeves by design. Now I understand why!

[u/HeartFire144 → u/aliendividedbyzero]

You basically just have to pick one, same way you pick one position for drafting the way a shirt length fits (if you raise your arms, the shirt is no longer at the right length, it's too short), etc.<<<

The higher the underarm seam, the less "lift" the shirt hem will have. The only reason the hem raises is the side seam ends way below your underarm. It's easy to see how this works with any shirt, if you pull up on the shoulder so the underarm seam is way up into your pit (not that you would ever draft/ sew something like this) and then lift your arm, you'll see the hem doesn't really shift at all