I use 1.75mm Zing-it for all my tarp lines because:
1. It's more than strong enough.
2. It's yellow but not reflective - keeps me from tripping without being a lighthouse.
4. I use it for everything including hammock ridgeline & stuff sack cord.
5. Doesn't tangle.
6. I buy the 180' spool.
I have 9' of it on each end of my tarp attached with Klemheist loops and a Dutch hook on the tree ends. I wrap the cord around each tree and hook it onto itself. Then I slide the tarp into place using the Klemheist loops.
"Life is a Project!"