The video tutorial for sewing the double-layer collar of a sweater is as follows:

Preparation materials: sewing box, sweater.

Operation steps:

1. First, fold the collar in half and sew.

2. After aligning the collar, use the needle and thread to pick up every two stitches at once.

3. Don’t close your head. Every two stitches in a group must be aligned.

4. The two needles in the last group must be fixed and hidden.