I tend to use nothing in warm dry weather and have managed with a space blanket in winter.

I'm considering making a bathtub groundsheet like this http://www.backpacking-lite.co.uk/diy/m ... floor.html - probably out of silnylon.

So what do you use? Does a bathtub make a big difference? What's the best fabric to use and does anyone have a neat trick for making silnylon less slippery?

Poly Cro double glazing sheeting. Weighs nothing and is cheap/disposable.

In no real order, I have used:

•Polycro ... as Dan says, light and pretty tough.

•Tyvec ... not fully waterproof but near enough but quite heavy.

•Sil' ... run lines of silnet on the material to stop it being so slippery.

•PU coated nylon ... heavier than sil' but not as slippery.

•Cuben ... works as you'd imagine but obviously it costs.

•Poly dust sheet ... cheap , works well enough.

•Some really weird dust sheet from the pound shop. No idea what it was made from but the fumes it gave off must have been toxic.

•Waterproof map ... 2 birds-one stone.

One thing to consider ... while a bathtub will help keep water out, it'll also keep it in. Any condensation, etc that drops off your tarp soon starts to pool when it can't escape/run-off.

Interesting. So is it worth making a proper groundsheet? Is there any real advantage over the cheap, disposable options?

So is it worth making a proper groundsheet? Is there any real advantage over the cheap, disposable options?

I think it depends what you want it to do. I made the one in the pic to act as a wind-break when a tarp was set quite high. If you just want it to keep you and your stuff off wet ground, then possibly not.

Like it.