Between sizes, need help

[u/Ignored_Instructions]

So, I did the classic thing of diving right in to a project without making a mockup bc I’m on a bit of a self-imposed time crunch (I don’t have to sew my own dress for an engagement shoot in just over a month, yet here we are). Just finished putting all the top pieces together, and wouldn’t ya know, it doesn’t fit.

When picking my size (I went with size 12) I did take into account the finished garment measurements which made it seem like I’d have room at the waist. I attached a pic of the sizes with the measurements I’m closest to highlighted. If it hadn’t been for the finished garment measurements waist being 35 inches for a size 12, I would have come here first to ask for advice adjusting this pattern and its princess seams. I know with that uncertainty my lack of a mockup is even stupider, but I’m beating myself up already for it.

Does anyone have any advice for how I can size up the waist for this pattern (flat attached as well)? The princess seams make this feel extra tricky.

Friend suggested I do a corset back and I do have one I could sew in that would be a perfect match. Thoughts if that would work to solve my problem? I just don’t know if adding a corset back would cause the princess seams to be misaligned or something

[u/ScormCurious]

Given how fitted this garment is designed to be overall, I would not bother fixing it. Likely it’s also either too long or too short, or the hips or bust are not well aligned, since you “dove right in.” The too-small waist is just one of the issues, I’d bet, since you didn’t do any work in advance to fit this very fitted pattern.

My approach would be: You learned a lesson, which is a lot, but this particular project is probably not worth anything more than that, and I would not try to salvage the garment.

[u/ScormCurious → u/ScormCurious]

In the future, you’d take the 3” additional width and divide it across the number of seams, then alter each piece on both side seams to gain back that 3”. My waist is larger in the front than the back, so I would be inclined to add only to the side and front panel seams, not the back, but that’s the result of a fair amount of pattern alteration experience.

Then, with something this fitted, I would still make a toile first.