I am sorry you all, I didn't notice the discussion about the breaking strength of the ridgeline. Read this page about adding a ridgeline by Jeff:
From that page:
First, choose your cord. Anything with a breaking strength of about 200-300 lbs should work, but just like hammock supports it should probably be low-stretch. I've had 550 cord stretch so much that it wasn't useful. I've also used BPL Air Core 2, which is very thin and light so I thought it would be perfect...but it was so thin that it was damaging the hammock supports. Right now my favorite is BPL Air Core Plus...it's really too expensive for this use, but I had some already cut to the right length so I put it on there. Webbing can also work.
Regardless, my stuff won't break. It is the same as I use for the support lines. Looks better that way, anyhow!