Use a footprint that fits tight

Yes, size matters more than material for preventing condensation.

Condensation between your tent floor and ground cloth happens when moisture gets trapped in between. The most common cause? A ground cloth that sticks out past the tent edges. Rain hits the exposed fabric, water pools under the tent, and now your floor is sitting on a wet surface that can’t dry. Keep your footprint at least an inch smaller than the tent floor on all sides. No overhang. No exceptions.

Material wise, you have two good options: a custom footprint from your tent brand (they fit exactly) or Tyvek HomeWrap. Tyvek breathes just enough to let moisture escape while still blocking sharp rocks. Cheap blue tarps work great for abrasion protection but they’re non-breathable and will trap moisture if you pitch on damp ground. I wouldn’t use one unless the campsite is bone dry and I’m okay with a risk of pooling.

A ground cloth’s job is to protect the tent floor from punctures and dirt. That’s it. A good one does that without creating a second waterproof layer underneath. Polycro (window film) is lighter than Tyvek if you’re counting grams, but it tears easier. Either way, cut it small, keep it snug, and you’ll stay dry.

Better to have a slight gap than a big overhang.