I want to make a basic lightweight foot print to replace my inner tent. It is made from 75D polyester Taffeta 185T, 6.000 mm, 100% polyester.

I will just want to make a basic rectangle 90cmx200cm to put my mat on and want it lightweight but waterproof.

Any suggestions for what fabric I need to get?

Ta.

Permavent or Tyvek ... Stu sells them both.

Permavent?

Crikey ... there's an echo in here.

Polycryo aka secondary glazing film, I use a wide piece folded in half to prevent tearing and snagging on wet boots.

Tyvek is okay but it doesn’t stay waterproof for long, if that’s a concern

Polycro is great, very light, very waterproof and very cheap. Just crinkles a bit and can be slippery but when a box of double glazing film gives you enough for about 7 years of bivvying it’s a no brainer

Are you pegging it down Steve?

No mate, just lie it on the floor and use shoes and bags to hold it down. If it's windy just fold it so the bivvy bag doesn't leave much to flap. I only use it to stop my bag getting wet and dirty, but it would work under a tent no problem.

Cheers all will msg Stu.