OK don't laugh, I think I invented a seam. I've consulted my book of Complete Dressmaking Skills and it's not in there...
What happened : I'm making a shift dress from drapey polyester and was about to 'overlock' the seams after sewing them when I realised - too late, as per - that I should have done French seam as it is likely to fray away to nothing the messy little swine, and overcasting will look reight rough.
Not wanting to unpick a perfectly good seam I folded and pressed both sides of the seam allowance in on itself and stitched it together on the fold, capiche? (If I could post a pic I would but need instruction on that
)
So, it's a hybrid flat fell seam and French seam - a French fell seam p'raps?