Seams To Fit Part 1: A Little Less Laxity - Learning Precision

I'm improving a lot of sewing skills while working on my bustier project. For one thing I'm doing more pattern work, which is not only helping me to practice creating a physical pattern (I began with a commercial pattern and altered it - a lot). Also I'm learning to use the actual resulting pattern in new ways. 

I've changed my concept of when to create a seam allowances, at least for this very fitted garment. 

Creating a pattern with no seam allowance, is starting to be useful

Typically, when working with a woven fabric, I've used the standard 5/8" seam allowance that comes on a commercial pattern, or else added that same measurement to my own pattern. I knew that traditional patterns are often created with no seam allowances (Burda Magazine patterns are an example), but I didn't understand why that was done. Now I have a reason to leave that allowance off the pattern.

It has to do with fit.

I don't usually make fitted garments. If the seams I sew in, say, a loose shirt project aren't absolutely, precisely the same as the original pattern it's probably not a big deal. I sew the back to the front at more or less 5/8" away from the cut edge. A little extra or less between a couple of friends, and you're not going to notice the lack of precision in the finished project. 

 A bustier, however, is an ultra-fitted garment. In addition it covers much less body area than that loose shirt. Oh, and by the way, instead of that loose shirt's one back and one front piece - the back of my bustier is three pieces. The front is five pieces - several of which are extremly narrow. And those eight pattern pieces cover less surface area than the loose shirt's two.

If I'm at all casual about the seams whose positions I've carefully detailed while fitting this pattern, the garment is in danger of being too tight to fit. Or it may simply fall off!

I need to know, when I sew, that the seams I planned to sew during the fitting stage, are the ones I actually do sew. The first important thing I do to achieve that goal, is by marking my seams accurately. My goal is to get the seams within 1/8" of what I've decided is correct. I may still loose a little one way or another. My final back and front seams will make up any final corrections, but if it's very much off it will be noticeable. I want to avoid that.

Next Posting - Seams To Fit: Making My Mark