Echoes Of Alterations Past

In Sandra Betzina's book Fast Fit is a section called Sequence For Pattern Alterations. It's intriguing to me how vastly different the results can be depending on in which order and by which method an alteration is made.
The measurements in the muslin above are the same as those used in the one blow. Above, I made a narrow back adjustment from shoulder to waist and below I made a narrow shoulder adjustment using Sandra Betzina's template method. This raised the underarm point and shortened the armhole by 1/2" which is the same amount as the tuck above. The tuck at the waist is removed in the muslin below.
Once again, I love the way this muslin fits EXCEPT for the excess behind the armhole.
The pivot point is crucial when making adjustments. The green line is the original angle of the front armhole. The pink line illustrates the same angled pivoted from the middle. It came all the way out to the end shown and would have widened the front. When I saw that I realized I must have done something wrong and re-read the instructions. The black line is the same angle pivoted from the new shoulder point as instructed.
badmomgoodmom suggested comparing the draft to the armhole on a Burda pattern. In the illustration above, the bit of green at the armhole is the original seamline. The pink line is a guesstimate of how much further in I think the seamline should be. The cut edge of the paper is the seamline used for the blue muslin above. The pattern is Burda 2964. If I narrowed the shoulder width on the Burda pattern, the lines would be virtually the same. Where I need less fabric is directly behind the armhole at the underarm but with more ease than above. 
When I thought about it, I realized what was needed was a version of the narrow chest adjustment adapted to the back. For that adjustment, you cut across from the underarm, fold out the required amount, and then add the same amount to the front seam of the sleeve. This prevents the sleeve from twisting. I needed the entire armhole to move over at the back without removing all the ease and making the garment too tight at the underarm.
I picked this fabric to differentiate from the blue and didn't realize it would be so difficult to see. Hopefully you can. In the back, I made the same 1/2" narrow back adjustment from shoulder to waist as sewn with the green muslin above and then I added 3/4" to the side seam at the underarm merging it to the hip and added 3/4" to the back seam of the sleeve to prevent twisting and raised the underarm point by 1/2" to match with...
... the undearm point on the front which was altered using a 3/4" narrow shoulder adjustment with the template method. The bust point was not altered for this muslin because I wanted to keep the comparison consistent without adding a new detail. I'll change it for the final draft.
Adding 3/4" to the back seam of the sleeve allowed it to have sufficient width to wrap around the arm without stretching and pulling. My arms hang forward which always impacts how the sleeve hangs. If it's a short sleeve that ends above the elbow, it'll hang straight but if it's a 3/4 or long sleeve, it'll have a wrinkle from the forearm to shoulder. Sleeves with elbow darts eliminate that problem.

Marcy made a comment this past summer about a skirt and top that I was wearing noting that the back fit wonderfully and that the back always tells the story. I couldn't agree more. It upsets me when the front fits really well but the back is a mess of wrinkles. I take a lot of teasing about the degree to which persist to resolve issues but it's important to me and what's the point of sewing your own clothes if you can't make them better than ready to wear.

In the past two days, I've sewn about ten muslins of this pattern each one with a different choice of alterations and have achieved a fit that I think is much improved on the starting point. This black and white muslin is very comfortable. It skims the body without clinging, there are no pulling points of tension, and I can easily move my arm forward and up. In the process, I've eliminated three alterations that are no longer necessary and streamlined the shoulder process. Success ! ! ! And now that I'm happy with how it fits, I can play with this pattern for a while and see what happens and then transfer the learning to another pattern.
Last fall, I figured out a T & T t-shirt pattern that works. Now with this blouse pattern, I have a wider range of top options and the information can be transferred to jackets and dress bodices. Skirts have never been  difficult to sew which could be why I love them. Pants are another issue entirely. Granted, I've lost some weight and inches but this is what the back of my jeans look like. Horrible. Howard says no one notices. I don't believe him. I notice and I hate this look. It's why I have always preferred the way a trouser cut falls from the hips. Far. More. Flattering.
In the workshop I took with Sandra Betzina a few years ago, she told me that I'd have to sew jeans with a center back seam or learn to live with the wrinkles. They are starting to really Really REALLy bother me - so much that I typically wear a skirt when I go out in public. I'm just about ready to start playing with Sandra's out of print Vogue 2948 pattern and see what I can come up with but I'm not sure if I even should bother. I can sew trouser style jeans and they are more flattering on my figure. I just worry that they look like Mom jeans and what are Mom jeans anyway? How do I not cross that line? I'd appreciate some feedback.

Talk soon - Myrna

Grateful - a T & T blouse pattern