A seam allowance is the margin left outside the stitching line. A generous seam allowance.
It has to be the same on every piece or nothing will fit together. A large seam allowance lets a garment be let out later, which is why children's clothes have one.
1nounseam allowanceThe margin left outside the stitching line.
“The pattern called for a seam allowance of one and a half centimetres.”
seam allowance is a margin.
Practised in Knitting & Sewing