You can also use a heavy denim instead of coutil.
Using the larger grommets here (if you have them) will allow you to use any lacing material you may have on hand for your fitting.
Say you are making your dream dress, copied from an extant (existing) garment. You study, you plan, you search, you find. You sew, you tear, you wash, you iron, you cut, you sew some more, you rip out, you stitch, you hem, you attach. After hours of work it's done. It is beautiful.
But why doesn't it look like the original? You analyze every detail you can find about the special gown. You've copied it exactly. But then why does it not look the same? What's missing?
And all 325" of bias cut and ready to make piping. Now I just have to cut the linen underlining and the muslin skirt hem facing. I can't wait to start sewing as that'll move faster than the cutting stage (which it always seems to do).
In sewing, half your time on a project happens BEFORE the construction. And then, half your construction time is spent at the ironing board (as it should be).