Nemo footprints are an exact fit to the floor of the tent there's no surplus material or weight.
Nemo Equipment says:
You don’t need it for waterproofness, NEMO floors have that covered, but if you will be spending a lot of nights on gravel, this could add longevity to your tent.
Most manufacturers recommend the use of a footprint to extend the life of the groundsheet of your tent, but if you've just bought an ultralight tent do you really want to carry the extra weight associated with it? And if you always need a footprint then why don't the manufacturers just beef up the floor fabric?
Our recommendation is to use a footprint if you expect to be camping on rough stony ground - Corsica's GR20 is a good example of this, and leave it at home if you are not. Some footprints have other uses, such as being able to pitch just the flysheet and footprint together as an ultralight shelter - so in this case the footprint provides you with increased flexibility in your shelters.
- Reviewed by Ultralight Outdoor Gear