This tailoring adjustment involves removing the original hem stitches, pressing the crease flat, and creating a new hem closer to the raw edge of the fabric. Tailors perform this operation to lengthen trousers, skirts, or sleeves for taller wearers or growing children. It relies on having sufficient seam allowance left inside the original fold.
Heard on the job
I need to let down the trousers by an inch, so unpick the blind hem and press out the old crease.