I don't really use french seams, though of course I love the idea of seeing no raw edge!
My brain is having a hard time fathoming that it's as easy when the seam is a curve, but maybe I'm just having a hard time visualizing it >.< Doesn't the fabric pull funny? French seams are best used on straight seams, am I right?
Also another point is that when working with a pattern, the seam allowance needs to be doubled, since you're sewing the seam twice! I can only imagine the agony of realizing the garment is too small!
I honestly have no idea how they'd work on a curve but I'll look into it! Since this is a technique generally used for fabrics involved in intimate apparel I think it probably wouldn't be that much of an issue since delicate fabrics would be less likely to be all bubbly and retarded.
nah, it should basically take up about 1/2 inch seam allowance if you're doing it right. Just make your first seam with VERY little seam allowance and it shouldn't be a problem, I think.