Just a quick post showing a few details of a unique silk hook and eye closure on one of my Stella McCartney bras (manufactured by Bendon)
The entire hook and eye closure is made from silk and has no edges. Essentially it completely bagged out and lined.
I believe it would be recreated if after creating the hook and eye section cutting a piece of silk the width of the hook plus the amount you want it to wrap around plus about 1/16″ for turn of cloth then stitching that piece about 1/4″ away from the edge of the hook on the sides and about 1/8″ on the edge and then turning it inside out so the silk wraps around the edges and you have a clean finished back.
It’s a nice detail though I’m not sure how sturdy it is long term you can see how much wear there is from one wearing plus one washing.