I think that in order for me to get the right shape under one of these gowns, I need to make a corset. I could stiffen the heck out of the gown itself, but that's a lot of stress on the fabric, so the bodice would break down faster, and that also means that I would have to do this every single time I make a new gown. With a pair of bodies, I can just build all of my garments over the same foundation garment and not have to go through this step each time I want a new outfit. I also plan on costuming later in the period as well, so if I make something that will work under an Elizabethan gown (because really, most of our evidence on how to make these comes from then anyway) it can do double duty and work for that period as well.
Now, my corsetry experience is modest at best. However, I've learned from my duds. I've learned that compressing the bust too much isn't attractive. I've learned that if these are too flimsy, they'll fall apart after your first wearing, but if they're too bulky they won't work right, either. I've also learned that coutil is too dang expensive to mess around with when I don't really know what I'm doing. Because of this last point, I went to Jo Ann's on a mission to find a sturdy but flexible fabric with a little bit of slip and not a lot of stretch. Behold: canvas twill! Yay for twill; it's extra strong, and hopefully will keep my bones from poking out through the fabric. I've also read that cutting one layer on the grain and one layer across the grain will help make these stronger. I don't know if I believe that it will be stronger, but I do believe that it won't stretch as much. And when you're making a corset, a little stretching is to be expected, but a lot is bad news. I'll just have to be careful to baste and top stitch a little extra, because if these pieces do stretch despite that, they'll stretch differently, which is no bueno. I am also doing a layer of silk that was a red tag fabric at Jo Ann from the home decorating section; it's a dusky pink with woven, raised stripes on it. I figure the silk will breathe better than a synthetic, and even though I know it doesn't really matter whether this layer is pretty or not, I love the idea of having beautiful underthings.
Here is a picture of the pattern I am using (Simplicity 2621), as well as the materials!
One thing about the pink silk that makes me nervous are the stripes. On the one hand, it may help to conceal some of the stitching for the bones, or at least act as a guide for me to sew them more precisely. On the other hand, if my casings aren't stitched perfectly straight, it will be more obvious with those stripes to compare to. I'll have to be especially careful about cutting EXACTLY on the grain and stitching really precisely!
The one material I don't have yet is boning. I'm not sure if I want to use flat steel, like I usually do, or try something like cable ties. Cable ties are more economical, but aren't as supportive. I am also concerned with them warping and holding my shape and not springing back the way steel will. I also haven't decided if I want to include a busk or not. If I don't use a busk, I could make this front lacing, which would be really nice and convenient. However, I don't want the lacing to show through the gown; I have seen front laced corsets that don't show at all through layers of fabric, but I'd hate to risk it.Then again, having a back laced corset AND a back laced gown might not be great, either. Side lacing? I feel like that would warp the shape of the corset a little bit... Instead of pushing things in, it might smash them out, instead. If that makes any sense. Frankly, I'm just not convinced that a corset for this period needs a busk; lots of paintings show a slight swell at the breast under garments, suggesting to me that whatever support garments were being used were at least a little flexible. And not that costuming is about comfort, but I think not having a busk would be more comfortable, which in turn helps make an historical costume look more like clothing when worn. One thought I had was just to put extra bones in the center front, and perhaps use 1/2 inch wide steel instead of the narrower kind.