March 18, 2009

grading seam allowances

After the seam is sewn and pressed the seam allowances are trimmed to reduce bulk. First the seam allowance is cut in half.

Then the side of the allowance that will lie closest to the outside of the finished garment is trimmed in half again.

The graded seam allowance looks like this.


  1. Question: why do you use ½" seam allowances then? Why not just use ¼" to start? It would save fabric, save time and be more accurate to sew.

  2. Hello Alison! The final seam allowances, once trimmed, end up being 1/4 and 1/8 of an inch. Working with a 1/4 inch seam allowance from the get go is fiddly. Working with an 1/8 would be miserable. The narrow seam allowance is more difficult to press too. It's easier and faster in the long run to use the wider seam allowance and grade it.
    Thanks for the question!