The last few shirts and suitjackets I’ve made muslins of have been decidedly underwhelming in regard to fit. I’ve never made any shirt that felt truly comfortable, and they always seem less flattering than what I’ve had in mind, at least in the shoulder and back armhole area.
I tried a broad shoulder adjustment which resulted in shoulders that hung off my body in such a way that my actual shoulders were not inside the sleeve shoulder and could not move.
I have tried a sloping shoulder adjustment, which definitely did not work.
I tried adding width to the back bodice piece center back, thinking my shoulders were broader in the back than typical patterns allow for. That messed up the front fit.
My current fit hypothesis: I need a forward shoulder adjustment for my slumping posture, a way of dealing with my broad/weird back, and an accommodation for my broad rib cage/small bust combo. Oh, and my nonexistent waist may come into play also. Phew!
So I found this extremely helpful blog at A Fashionable Stitch by a woman with a similar shoulder issue in the back. I’m not sure if mine is a large shoulder blade, but our body types sound pretty similar and I used her advice (she explains it in detail, but to summarize badly, add to the back of the sleeve, sort of flattening and expanding the curve of the back part of the sleeve cap, and add a bit of extra width to the back bodice in the same armhole area). Since I also have a somewhat broad rib cage I add about half an inch at the bottom part of the armhole (the point where it meets the trunk) and then taper that down almost to my waistline. And magically, on the muslin I recently tried of this, my arms FIT!
I used advice from many sources on the enigmatic forward shoulder adjustment. Interestingly, this doesn’t exist in any of my vintage sewing books, which makes me wonder if it’s a posture issue that has only recently become common due to lifestyle changes in the last, eh, 30 years like large amounts of computer time, texting time, stooping over screens. But I digress. Essentially what I did for this is lay out the pattern pieces with all the pieces touching where they meet and adjust the line of the shoulder seam on all pieces to angle forward. I am adding to the back and reducing from the front. The pattern shape stays the same but the lines move. The armholes also stay in the same place. More on this later, maybe.
So for the weekend I’m going to try a princess seamed simple blouse with all of these adjustments. I’m sewing with a vintage Singer 348 that I bought because it was “owned and perfectly maintained by a professional seamstress” except that apparently she didn’t know how to clean out her bobbin case. It was the dirtiest machine I’ve ever seen. More on this later, too. Anyway, this is her maiden sewing voyage with me, and I’m trying to get a feel for whether she might need a belt replacement. I can’t tell if the slippiness is something I’m not used to because I don’t usually sew on a belt driven machines, or if (as I suspect) the belt is old and not as effective as it should be due to time.