SC + mitten hook = 2 grams
Buliding on previous ideas, I made 3 Tarp Ridegline Reefing cords that weigh 2 grams each. For the BigMamajamba, it seems to only require 3 cords at 6 grams total.
1. Make loop at each end of small 12" shock cord (1gram).
2. Larkshead one end to small plastic mitton hook (1gm)
3. Then larkshead the hook through the other loop onto the RL.
4. Roll tarp up and hook the mitten hook to either the SC or RL
With SC, it can be easily moved up and down the RL but has enough tension to stay in place.
Works fine whether RL is over or under. If RL is under (like mine), just flip one side of the tarp over to the other side and it will now be hanging as an over the tarp RL for purposes of rolling up the tarp onto the reefing cords.
PS- not sure if I have the terminology correct for some of this!