My wife and I just got back from a rainy trip on the Beartooth Plateau with a friend, and the conditions made us see the need for a new shelter that better suits Montana conditions. (As opposed to our Firstlight, or the small tarps I've been used to using in the southwest.)
We're tossing around designs for making a Pyramid tarp. It would be useable for 2-4 people in all seasons, from mosquitos in early summer to mid-winter ski touring. It would be light of course, but more importantly would be 100% bombproof.
I'm thinking 1.9 oz Silnylon (from Seattle Fabrics). I've used it for packs and clothing, and it works very well. It comes in 60" yards, thus making an overall bottom length of 112" (with two-panel sides and generous seam allowances) convenient. I'm also thinking an overall height of 72" would work well.
My questions are several:
-What seam style would be most effective for the main seams?
-Should the 10-12" of mosquito netting be placed right along the bottom, or sewn a bit higher along the sides?
-I'm thinking that eight tie points are necessary along the bottom (corners and mid points). How necessary are mid point guy points (a la MLD)?
Any other thoughts are also very welcome.

