Explanation

Seam allowance is the extra fabric between where you sew and where you cut. This space provides room for stitching and prevents fabric edges from unraveling.

Standard seam allowance is usually 1.5 centimeters or 5/8 inch. This extra fabric gets folded inside the garment after sewing the seam.

Darts are folds for shaping. Grain line shows fabric direction. Notches are alignment marks. Only seam allowance describes the space between stitching and cutting lines.