A welt pocket is a slit in the fabric, faced with one or two folded strips. It is precision work, and every step depends on the one before being accurate.
Interface first. A rectangle of fusible interfacing on the wrong side behind the whole pocket area. Without it the opening distorts and the corners fray.
Mark accurately on the wrong side: the opening line, the two ends, and the welt width. Use a fine chalk line or thread tracing. A millimetre of error here is visible in the finished pocket.
Stitch the rectangle. Place the welt pieces right sides down over the marked line and stitch two parallel lines the width of the welt apart, starting and stopping exactly at the marked ends. Do not overrun and do not backstitch — tie the thread ends instead, so the corners stay sharp.
Cut. Down the centre between the two stitching lines, stopping about 10 mm from each end, then diagonally into each of the four corners, right up to but not through the stitching. This Y-shaped cut is the step that determines whether the corners are square. Cutting short leaves a pucker; cutting through leaves a hole.
Turn everything through to the wrong side. Press the welts into position from the right side and check the opening is even along its whole length.
Secure the triangles at each end by stitching across them from the wrong side.
Then attach the pocket bag to the welt allowances and stitch around it.
Practise on a scrap of the actual fabric first. Nobody gets the first one right.
Questions people actually ask
My corners are puckered.
The diagonal cuts did not reach the stitching. They must go right up to it — the last millimetre is the one that matters.
Single or double welt?
A single welt is simpler and reads as a jacket breast pocket. A double welt is symmetrical and more formal, and it needs both strips to be identical.
Last reviewed 2026-08-11