Altering patterns to fit my body. Figuring out vintage patterns. Getting overwhelmed.

Hollywood Pattern 1555, my current project

 Oh the hours I've spent sleuthing the internet for an easy answer to my fitting problems. I've been posting my sewing projects over at Patternreview.com and recently a couple of other users gave me useful feedback on potential fitting/alteration needs for my body, including narrow shoulders and/or back, possible swayback (more inward curvature at my lower back than is standard), and a good reminder of my pear shape that could warrant a bit of extra room at the hip in blouse patterns.

You see, I'm just wrapping my head around pattern fitting and alteration. Using the book Fitting & Pattern Alteration: A Multi-Method Approach to guide me through basic understanding, I've been reading about body measurements, different methods of alteration, and fit analysis that gives recommandation for alterations specific to body differences and resulting fabric/clothing distortion. It's a lot to absorb and especially hard to try fitting myself properly without assistance from another person. Learning about pattern alteration would be easier if I were sewing for another person and could do fitting sessions with them, but it's a big time investment and I'd like to add clothing to my own wardrobe.

So here's what I've realized-- Generally I need to reduce some of the overall length in the back, as well as width through the upper back and shoulders, and possibly some width through the mid-back (armscye base to true waistline). I've lost a few inches on my bust, but there's still potential for a full bust adjusment (FBA) depending on the fit of the garment and designer (Colette Patterns designs for a C cup but most pattern companies design for a B cup). I've mentioned before that in sewing it's good to base your pattern size for blouses and dresses on your high bust (around back, under arms, above of breasts at arm crease level) for a truer fit instead of a full bust (widest point around breasts). This is a full pattern size difference for me and since I have a small ribcage and shoulders, I'm likely to get poor fit by choosing the larger pattern size. I'm getting lost in calculating how to do all of these things, or do something simple that will be a good fix.

The blouse I'm working on is a vintage pattern from the 1942, unprinted (uses perforations to "mark" waistline, grain, darts, etc) and with no mention of a standard seam allowance. UGH! The pattern says something along the lines of "small circular holes arranged like this represent 1/2" seam allowances" but there is nothing else defining the seam allowance of those that are unmarked. One reference I found online said 1940's seam allowances are typically 1/2", but another site mentions that sometimes main seams will be a 1/2" and side seams (which in my case is a big question because it's unmarked) could be 3/4". I read elsewhere that this variation in seam allowances is often given to allow for fit adjustment so I'm beginning to think I'll plan to just sew the side seams of this blouse to fit, rather than trying to find an answer to the unknown variable.

But I'm still going back to the fitting issues. Since the shoulder seam doesn't sit at the shoulder line proper, because the style has the back pattern piece extending to the front of shoulders and meeting front pattern piece at the gathers, I'm worrying that without being sure about neck/shoulder to waist measurements of the blouse that I won't get the fit right. And it's REALLY HARD to get a proper measurement of my shoulder and upper back width without assistance. Stretching to hold the measuring tape may be distorting the width-- I just don't know. So which pattern alteration do I complete first? Most references say length before width, so I'll address the issue of my typically short back length, then address the swayback, then address the width in the shoulders and upper back. I've measured the pattern pieces and compared to my personal measurements and they don't seem as far off as I usually see with modern patterns, but I also don't have any printed lines to use as a reference so I might be measuring wrong. UGH! I picked a tough pattern to approach alterations for the first time.

Ok, deep breath. I think I'll forget about the swayback adjustment for now and just adjust the overall length and width and see how it goes. I'm only sewing the "muslin" first with a polyester fashion fabric from Goodwill, then I'll re-address fitting issues before sewing the silk version. And then there's the question of whether I should alter the pattern to eliminate shoulder pads...

It's worth documenting that I also might add contrast piping to the collar and sleeves of the blouse for some definition, and I've already bought a kit for making my own fabric-covered buttons. These tutorials from Colette Patterns for making your own piping (already bought my cording!) and sewing piping into a seam will be useful.

PS. Since this pattern is old and crumbling I've already traced all the pattern pieces onto Sewable Swedish Tracing Paper and transferred the perforation markings with pen. I've got a version of a "printed" pattern now! I also scanned the envelope front, back, and sewing instructions to prevent further damage to the originals. They couldn't withstand actual use.

A few more links I've found useful:

•  Great tutorials on the Coletterie!
• Also, the industrial sewing tips at the Coletterie too.
• The Vintage Pattern Primer at Elegant Musings
• This PDF at Sewing Mamas has tips for vintage pattern sewing 
• As always, searching the message boards for helpful discussions like this one about swayback.
• Which is where I found this helpful swayback alteration
• Which resulted in loads of google searching, finding this alternative swayback alteration method.
• This guide to Pattern Alteration from New Mexico State University, a piece I've found very helpful since first thinking about the topic.