As noted in the FAQs, there are basically two kinds of glass tubing – filament and convolute wound. There are a few pros and cons I’ll expand on here. In the end, choose what is best for you-
To quickly recap the FAQ, filament wound tubing is wound at an angle, similar to a barber pole – except that it is wound up and down the mandrel, so it has a criss-cross appearance. Convolute wound tube is wound horizontally, over itself again and again, perpendicular to the mandrel…. sort of like paper towels on a roll.
Filament wound is probably a bit stronger than convolute, and it has a much smoother finish – so smooth, you should really rough it up with sandpaper before painting.
The bad news with filament? If you ever have a less-than-perfect end cut, it is very, very difficult to sand filament wound square. Convolute sands pretty easily. The biggest issue I personally have with filament is drilling a clean hole. Many of my rockets have a dozen or more holes that need drilled (vents, shear pins, static ports, perhaps a rivet or a screw for the ebay, etc.) Filament wound typically splinters, and the fibers can try to re-fill the hole, which is not cool for a static port… or they may cause a chute or a piston to hang up, which is probably disastrous.
Convolute tubing drills like a dream… almost like the material is made out of sugar! A very clean hole, every time. As far as strength? I have pushed convolute quite hard – and I haven’t folded it yet!
Finally, it is worth noting that filament wound tubing is much heavier than convolute. For me? Convolute – every time!