Set up the machine with a 90/14 topstitch needle and the 12-wt. cotton thread in the needle and the bobbin. Select a fagoting stitch (7) or any decorative stitch that is 6 mm wide.
Slip the cardboard spacer between the toes of the presser foot, and tape it directly in front of the needle on the machine bed (8).
Right side up, position the pressed lower edge of the blouse on the left side of the spacer. Right side up, place the pressed edge of the lower band on the right side of the spacer. Stitch so the needle catches the blouse edge in the left swing and the band edge in the right swing, joining the pieces. Press and set aside.
Finishing
Right sides together, lay out the two sleeve rectangles matching the embroidery. Pin on the pattern, aligning the hemline fold with the trimmed embroidered edge (9); cut the sleeves. Stitch the underarm seam, and stitch the sleeves to the blouse.
Finish the blouse according to the pattern directions.