A self-casing is constructed in a similar manner as as hem. Fold over the edge of a garment and stitch in place.
2. Turn casing to the inside of the garment along the fold line. Pin in place. Press outer edge of the casing.
3. Stitch close to the inner, pinned edge. Leave an opening to insert elastic as directed in the pattern guide sheet. If a header line is indicated, stitch along that line. Once elastic is inserted, adjusted and secured, sew the casing opening closed.