I use bungees and always have, however, if I did use cordage I certainly wouldn't bother with a ridge line.
I don't see any point to it. You can only hang stuff up outside your shelter if you have the line through your loops...or if it's inside then you'll get water seeping through where whatever is hung pushes against the tarp.
Bungees have to be faster than cordage as hooking on one clip is faster than tying one knot. Bungees auto tention your tarp so you don't need to mess about adjusting stuff. If somebody falls on or trips over your shelter or guy lines then the whole structure moves with them and doesn't snap.
You can make natural cordage if you need to but making natural elastic isn't so easy so the bungees can have more than one use...cataplut elastic etc.
And as for tearing a tarp....unless you have a very very very lightweight one then you'll be hard pressed to tear it unless something sharp does the tearing, certainly just tention won't do it....the military ones double as stretchers and I've seen one used as a makeshift hammock...if they hold the weight of a squaddie then your tentioning is unlikely to tear them.
It's horses for courses so by all means use what you like, the current trend in bushcraft is for cordage as that's what's shown in books and on the tele but I still prefer bungees.
It also never fails to amuse me quietly at various meets I go to when people have the tarp set up how you guys are discribing but they haven't used or tentioned the tarp on the ridge line and only the two end ones are actually touching the line...the rest are sort of levitating with the line through them...even in the photo below the next loop in from the edge is slack...why not ditch the line through them and just tie at each end as that's all that's holding it up anyway?
People say bungees are dangerous and can snap or ping off and have an eye out...well yes, that is true but you just need to be a little carefull with them. Last time I brougth this up there was heaps of people telling me that this bungee had broken or that one had snapped....after further questioning it turned out that these were old bungees (mainly used to hold stuff onto motorbikes - I use a spider myself on mine) and my answer was simple - CHECK YOUR KIT REGULARLY FOR SIGNS OF WEAR AND REPLACE ACCORDINGLY - if you do this then you are very unlikely to have an inncident.
As a final point, if you do insist on using the ridge line then can I suggest that instead of tentioning with the Prussik loop at each end that you instead use a Klenhist knot....it works exactly the same as a prussik but is the only knot of that type to release under tention....so if you need to adjust it you will be able to without undoing it.
Hope that's of interest to some of you,
Bam.
