Step 3: Nylon 'parachute' material
I've traveled with a piece 8m x 2m (weight = 500grams) & have used it for many things including:
1. replacing my backpack
4. summer 'sleeping bag'
.... etc, etc, etc.
Step 4: Fold material to suitable size
Allow enough space for wrapping up, to cover your goodies.
Step 8: Plastic Wrap
Step 9: The End
This saves about 8 - 10 kgs. (the weight of the backpack itself)
PS - if you wish you can 'cling wrap' a handle into the bundle for easier carrying.
Basic, but effective for those desperate to save weight !
Bon Voyage ...