Sewing lines (4)
I believe the answer is:
hems
'sewing lines' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for hems that I've seen before include "Fringes" , "Stitched edges of cloth or garments" , "Stitched garment edges for Shem" , "Stitched borders" , "Bottom edges turned under and sewn" .)