To make an invisible seam

To make an invisible seam :

It is used to sew the sleeves and sides of a sweater and is always performed on the right side.

1.      Place side by side the two pieces to assemble, front over, then string a needle with your thread.
2.      Insert needle through an edge stitch passing it under the thread between two stitches. Repeat on the other border to assemble.
3.      Continue that way every other row, not knitting too tight. Slightly pull on your thread to tighten the stitches: borders come together. The seam is invisible.