I've purchased some Sulky Solvy. It's a rinse-away stabilizer. It's not fusible, but it has directions for dissolving in water for brush-on application. I'm intending to try stabilizing just enough of the edges of the stretch fabric to cover SAs and topstitching allowances. Since it's intended for garment sewing I hope it's not too toxic. And less fumes either way.
Pora
I'm pretty sure Solvy is a film of PVA, polyvinyl acetate. Major ingredient of white glues. You may find that something like Elmer's School Glue works as well and is cheaper.
Kay
As for "fashion fabrics" I've used poly stretch satin and a light weight stretch denim (cotton).
The problem with the polyester is that as a fiber it is oil-philic (is that the right word?) it attracts oil. Which being that it is an undergarment near your underarms this can be a problem. Since body oil has a scent..you may not see it, but eventually you may smell it. Regular detergents may not always do the job to get rid of it. I've heard of specialty products out there, but haven't tried any of them.
Now if you wear the bra everyday for months this will be more of an issue that if you wear it once a month for years....
Cotton doesn't have the same, problem but I've noticed it does wrinkle up. Ok, so it's not bad enough that I have to iron it, but it does make the trip out of the wash look pretty mangled up. I've had more issues getting the seam along the cup to lay flat. Like it streched more while being sewn, I'm hoping that will get better. I also found to to be too restricive because it didn't stretch enough in the band for comfort, but that might be more of a "me" issue than the fabric issue", (it was about a 15-20% stretch). I fixed it by making the back band out something else (powernet works). I added a side seam so that from the front it all matches and from the back view it matches. The side seam is unnoticeable. Many RTW plus size bras have a support stay in the place anyway, the seam acts like a suport stay, without the plactic poking out.
I've lined the lower part of the cup with regular tricot and that seems to take care of the "itch,and comfort issue against the skin". I've also seen swimsuit fabric used, but for the lif of me I can't remember what the fabric content was.
For straps I've used a self fabric tube to match the cups. If I leave it adjustable, I don't use elastic, if they are fixed lenght I add about 4 inches of strap elastic attached to the back for comfort. I also used fold over elastic once in a pinch I doubled it and it worked out pretty good. That one is adjustable, but I usually don't have to. What determines adjustability is whether I can find rings and sliders to match. And time. Non-adjustable takes a few fittings to get it right, so it's faster at the sewing table to make it adjustable.
Hope this helps Raelynn
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