McCall’s 7058 muslin: FBA for princess seam, sway back adjustment, and gaping back armhole

I’ve been working on sewing up a new pattern release that will be used as a base pattern in an article I’m writing for Sew News. I needed to find a basic princess lined jacket to use to show the reader how to transform it with a few pattern modifications.  McCalls’ 7058 fit my criteria perfectly. I haven’t found any reviews for it yet, so hopefully this might be helpful to those curious to try it. I’m getting a little tired of making jackets at this point, but I must soldier on! mccalls7058But first, I’m making a version in some pretty Italian wool I bought at Britex a few years ago for a pea coat I tried to make Richard from a Japanese pattern book. The project was a failure, because I massively screwed up the welt pockets. I discarded it in frustration, and it’s been mocking me for a few years now.  I’m hoping I can salvage this wool, since it was really expensive compared to what I usually pay for fabric downtown. Hopefully, I’ll have enough fabric for view B.Italianwool

First, I made a muslin. I had a few adjustments to make to the jacket bodice; Adjustments for an FBA, a swayback, and a gaping back armhole.


Too tight bust

How I did my FBA

First I needed to determine how much to increase my pattern front for my FBA. I don’t follow those charts because I’ve often found they don’t work very well. What I like to do is make the muslin, then make little cuts at the bust where it’s tight. It will naturally open the amount I need. If I followed those charts you find in books and online, I’d have to increase my pattern by two inches, since I’m a D cup, to get the pattern to fit me. That formula should work assuming my pattern is perfectly drafted for a B cup. however, I naturally assume nowadays that the majority of pattern makers don’t really follow industry standards. It’s kind of a wild west in pattern design nowadays, with some people drafting patterns to fit their own non industry measurements, in the worst cases, then grading those non industry measurements, so you never know what kind of fit you are going to get anymore.

My slashes and muslin don’t lie. According to my slashes on my muslin, I only need to add 5/8 inch.  But I don’t like too much ease.slashedpattern

This is also really a great way to figure out where your bust point is. The cut fabric will naturally be at the widest point at the bust apex. As you can see, my bust is over two inches lower than my pattern! The reason it’s important to know where your bust point is is that that is where you need to slash the pattern for an FBA. If I slashed my pattern where the original bust point was on the pattern instead of my actual bust point, the fit would be off.patternapex
So much for all those bust exercises I’ve been doing at the gym. But I’m happy with my figure,even if my bust points aren’t up to par. Don’t let low bust points get you down. haha.

How I did my swayback adjustmentswaybackmuslinFirst, I’ve trained Lily my twelve year old, to pin properly at fittings, as I need someone to help with my back. She did a good job. Thank you Lily! I needed to remove 5/8 inch from the center panel tapering it to nothing at the side panels’ side seams. swaybackadjustment

The sway back adjustment is like the opposite of a full bust adjustment. Instead of adding length to the center panel you take it away, then on the side panel a slash is made, so the side seam is unchanged.

How I decreased the size of the back armholegapingbackarmholeSee how the back armhole gapes on my dress form? The dress form measurements are standard so that means it’s the pattern at fault here. Another reason not to trust textbook fitting advice here. If the pattern is badly drafted to begin, it needs to be fixed first.backarmholeI removed an inch from the back armhole. This was an easy fix since the princess seam goes right into the armhole.

Next up: I’ll have to adjust the jackets’ sleeve ease, since I removed an inch from the back armhole and most ready to wear jacket patterns have way too much ease.

Happy sewing and fitting! Stay patient, my friends!


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  1. Helene says

    I often have a problem with armhole gaping and swayback problems, so I found this post really informative. Thanks!