For each size up, add 12mm on the side seam and 6mm to the waist and crotch.
Please check that the pattern comes out with these measurement:
This project is great to use up all your off-cuts from past projects.
1) Cut the front once on the fold and the back once the on fold. Gusset cut one.
2) Overlock or zig zag gusset front.
3) Place the front onto the back, with right sides onto rights sides so that the crotch seam lines up. Place the right side of the gusset onto the back. Pin all 3 edges together at the crotch. Ensure edges are lining up.
4) Sew seam with a 1cm seam allowance. Use a straight stitch, 2 1/2 stitch length and back-tack at the beginning and at the end.
5) Flip the gusset to the front and tack the sides down to prevent the gusset from slipping around. For tacking, use stitch length 4.
6) Cut 3 strips of lace. For size medium: 2x 51cm and 1x 77cm.
7) Pin the lace onto the printed side of the fabric along the edge of the panties. The lace and fabric should overlap by about 1cm.
8) Use a zig zag stitch to stitch the lace down. The zig zag allows for more stretch. Stitch length should be 1 1/2 and stitch width 5.
9) Place right sides onto right sides and pin one side seam closed. Leave the other side seam open for now. Stitch with a straight stitch first and then overlock or zig zag the edge. (Straight stitch 2 1/2 stitch length). Remember to back tack at the beginning and at the end to avoid seams from coming loose.
10) Use the lace elastic piece which measures 77cm and pin it along the waist edge. Starting at one side seam and ending again at the other side seam. Repeat stitching as you did in step 7.
11) Place right sides onto right sides and pin the second side seam together. Stitch with a 1cm seam allowance and overlock or zig zag the edges.
12) To finish off your overlocking threads pull them back into the stitching with a large hand sewing needle as demonstrated in the picture.