Hope you don't mind me chimeing in but I've been doing some testing lately. Tent fabrics are tricky, each design has its own needs. Next to design, fabrics and how well they fit the design is second in determining how well a tent works.
Single wall tents are the most difficult and Bibler does it well. I know from working with AutoHome that each design has to have its own fabric because their needs are different. For example, the Maggiolina has a fiberglass top and bottom so it really needs to breathe, so they use a fabric that was created by Bayer chemical 40 years ago called Drylon. If you look at it in the light, it is a mesh, with thousands of holes. Because of its design with vertical walls, it works, but wouldn't work well if it was used as a roof. The Maggiolina need it because it has less fabric surface so the fabric has to really breathe.
The Columbus on the other hand can't use Drylon because it has an angled wall which acts somewhat as a roof surface. Airtex is the fabric of choice, and it was only developed something like 15 years ago. As far as I can tell it is very similar to Goretex using an expanded PTFE coating. Doesn't breathe like Drylon but you have more surface area so it works.
An aside about Goretex, Airtex and the like, while they are a great advance, they are expensive and don't seem to work as well in tent applications as opposed to clothing. From what I understand, the moisture has to condense on the mesh and then your body warmth and movement helps to pressure the moisture through. Water vapor just streams through Drylon on the other hand, because it is like a mesh. This is one reason why the Maggiolina is so good in extreme weather.
The folding tents are a different animal completely. The fabric has to be much thicker and have the ability to handle a lot of chaffing without harm. There was a cartop tent years ago that used a thin, backpacker type of nylon fabric. It would work when you got it but as soon as you went anywhere you would have holes develop. Needless to say, you don't see their tents anymore.
There is a lot of trial and error that goes into all this and unfortunately sometimes we have customers doing the testing. I had a wildlife photographer buy an OverCamp used it up in the Arctic and all over and a year later called me up and said the tent started leaking. I didn't believe him but sure enough, he was right, the first batch of OverCamps did have a flaw. The fabric was doubled at the top ridgepole for wear but where the stitching poked through could open up with extended use and allow a couple drops of water through. The tent's fabric normally swelled enough but they got over four inches of rain in an hour so it was an odd occurrence. Seam sealer fixed the problem but Zifer changed the design so this couldn't happen again.
There are some great new fabrics that are under development that I think may have great merit for tents. In fact I have an experimental drysuit that I'll be testing sailing tomorrow. Lab tests show that it breathes like Drylon but can be used in a drysuit, and it is quiet, very cool, but we will see.
Rich
