I have been thinking about my Tyvek tent designs again: I believe I can now make an approx 6 foot high, zero condensation ‘fire’ tent for 2-4 people which will weigh under one kilo including floor and zipperless mosquito netting and which will set up against a tree or with the aid of a hiking pole/stick. Similarly I think I can make a one person design (with about 1.5 mtre head height) at about 500 grams. It will be a few days before I have time to cut them out and make them as I have other projects. The beauty of Tyvek is: it is (relatively) fire/spark resistant (800C); it can be joined/repaired with tape; it is waterproof and breathable; it comes in 3 metre roll widths; it can withstand 160 km winds; it is cheap (30 metre roll at $180; ie 4-5 tents per roll); it does not drape; it weighs 1.7 oz/ sq yd (50gsm); it is white and has an R-rating so reflects and retains heat well – so wonderful for a winter fire heated tent. To my mind, a tent where you cannot stand/sit out of the rain whilst being warmed by a fire is pointless. Am also working on a sub 100 gram fire heated electric generator for charging batteries or electronic gear such as eBook readers/music players. I have no interest in making money out of these tents so will probably post the completed designs for interested folks in future. You do not need to be able to sew to make a Tyvek tent as it does not fray, can be joined with tape and works well with tarp holder tie-outs.