So I know this will be a storm of horrible risk and potential disaster, but I need some advice with the following idea.
I want to make a corset, for a cosplay, that has a high back and a zip front, with back lacing. So far, so good. I have a mockup, from Laughing Moon's Dore corset, that I'm beating into shape and the mockup is looking mostly good at this point. The fashion material I'm using is faux leather from Joann's, and the inner strength layer(s) is coutil from Richard the Thread. The zip isn't totally determined, but is probably a metal separating zipper, somewhat fancier (certainly more expensive!) than a YKK zipper, and the lining is probably cotton broadcloth, fused to coutil. I have two concerns, one about the zip front, and one about the material itself.
1) I decided that I wanted to add fingers across the zip and use swing latches to close the fingers. I am mostly worried about balancing the strain on the zip - at least in the mockup, the corset is pretty tight, though it doesn't provide much reduction. I can use the corsetmaking.com bone for the latches on the one side, but that's not an option for the finger side. In addition, I need to strengthen the layers so that the pleather has minimal opportunity to stretch. My thought there is that I will fuse a layer of coutil to the pleather on all panels, as well as one to the lining, and then treat it like a dual-layer corset.
However, that doesn't support the fingers very well, and I can't visualize how to get the zip in. My best thought on that at this point is to add a third layer, this time of a single layer of coutil, that is the shape of the front panel minus the fingers, and sew that to the lining side, using it to hold the zip in place. I will also run maybe a half-panel of the lining from the center front of the center front panel out to the fingers. Given that I want the fingers to lay flat against the front of the corset, that suggests that the fingers need to be somewhat tight.
Have I planned this well, or is there a better way to go about this task? Is there anything I can/should use in the fingers themselves to stiffen them further to provide support for the swing latches? Would putting the swing latches on either side of the zipper be a better option and still give room for me to use the zipper?
2) Pleather stretches. I have another corset from Richard the Thread's coutil, which has a narrow herringbone weave to it. That corset is two layers of the coutil and a layer of crap dead dinosaur for lining, with the occasional decorative thin pleather bunged on in various places. I haven't overtly noticed the corset stretching, but I did notice yesterday that I have a lovely rippled effect happening around the grommets in the lacing - I put a wide piece of the very thin pleather (not the quality I want to use for the new corset, which is substantially thicker; this was a remnant from a purse making project) at the cf and cb, both of which are laced, and it looks like the grommets are still holding, but the stress is starting to pull them - the "dip" in the curve is right at the grommet, and the "rise" in the curve is actually the original straight line of the seam. The corset appears to be otherwise undamaged, and the pleather does not appear to be coming out from under the grommets at all. So what's stretching? Should I worry that something clearly is?
And with that in mind, assuming that I have no money to spend (because I do not) and have the materials I have, how could I minimize the stretching of the pleather in the new corset? Is there a particular way to cut the coutil so as to minimise that? As mentioned above, I do plan to fuse the coutil to the pleather, but I'm not sure if that will solve the stretch problem. When I'm looking at a herringboned fabric, I'm not sure if straight-of-grain or cross-grain is actually less stretchy; my assumption is that it all behaves as though it's bias-cut.