The seam is worked in two steps starting from the top of the shoulder. Pull half of a piece of thread through to the right side of the sweater.
Take a stitch from the rows on the body of the sweater by catching the bars between stitches.
Then take a stitch from the sleeve by placing the needle under one knit stitch of the sleeve.
Repeat these steps until you reach the seam under the arm. Pick up the other half of the thread at the top of the sleeve and sew the other half of the seam.
It helps to have a quality control inspector on hand.
I’m making progress on the Latvian mitten and will take photos this weekend.