1. Lay the bag out on a flat surface and folded back ~ 25mm (1”) around the open end (A-B)
2. Make a 25mm cut in the folded plastic 3. Lay the elastic (C) inside the fold and have the two ends exit through this cut
4. Tape completely along the folded edge of the plastic with the sticky tape
5. Place a cut in a ~ 60mm piece of duct tape and fold this over the exiting elastic to strengthen this part of the bag
6. Thread a small wire tie through two cuts in another piece (~50mm) of duct tape and stick this to the inside of the bag ~ 15cm up from the elastic (E). This can be used to secure the plastic helium hose inside the bag.
7. The toggle (D) (or other fastener) is then threaded onto the two ends of the elastic to complete the bag (Fig) and attached to the bagusing tape