Creating a contrast shirt sleeve placket

Mark the placket location
Cut a contrasting fabric strip 18 cm x 14 cm
Stitch 1 cm from the line to 1 cm from the top of the piece.
Place a piece of the main colour, cut to 20 cm x6 cm
Stitch the same as the other piece, stitch across the top, joining the two seams.
Cut through the sleeve along the line, cutting to corners at the top
Pull both pieces to the front side of the sleeve, finger pressing the seams toward the centre
Press a small (5 mm) seam on the outside edge of both pieces.
Top stitch the contrast piece in place.
Fold the upper placket over the lower, press.
Press the top to a point or square, depending on preference.
Use a fabric glue stick if the point won’t sit properly, keep the glue away from the edges.
Topstitch the top placket, crossing where the two pieces meet.