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Another benefit you didn't mention, If you're camping somewhere muddy it's great to be able to pack a clean tent separate from a slimy footprint

I remember you commenting once “I’ve never used a footprint on any of my expensive tents and they’re all fine” where someone responded “I wish I had many expensive tents, but for a few ounces a footprint is worth it to protect the one I have”

Cleaning my cheap tarp ground sheet has been easier than cleaning the bottom of my tent.

Could you please put a sheet of tyvek through your puncture, abrasion, and waterproofing tests to see how it holds up vs tent floor fabric? If it does better, that would immediately justify putting a sheet of it below your tent as a footprint

The 2 main reasons I like one. The bottom of the footprint is always damp when I pack up in the morning, the bottom of my tent is dry however. Secondly it gives me a nice clean surface to work on when pitching and taking down the tent. For me the $20 and couple of ounces is worth it.

I appreciate the efforts to test things scientifically. But to me it appears that you often come into these tests with your decision made and, unconsciously or not, pick tests and interpret conclusions to siut that preconception.

Might be mundane but I would rather clean a footprint than my tent if the ground is all muddy which in the UK it often is.

I run a textile testing lab, incl waterproof products. You did a pretty decent job all things considered. I suggest working with a lab to design some real world testing as a next step. You would be surprised how textiles can often fail. Tensile testing, grab testing, wash testing, resistance to UV. Other commenter's make good points such as keeping the tent clean, etc. I would add that I have camped on ground with lots of rocks and sharp objects that cannot be removed. The rest of the campsite was muddy and boggy. It's why I car camp with an elevated tent. Oh, on waterproofness, if water gets between the foot print and the tent, then it can fail much quicker as pressure builds up versus soil which is permiable. Or with chairs or camp stretchers create a localised high pressure zone.

You are missing the point pal! Im wild camping in the middle of nowhere in Scotland just now and I got this tyvek large underneath my X-mid because some grounds are muddy and a mess or often thorns and other sharp stuff you cannot always see and the most important is to protect my new thermarest xlite as mats are expensive these days...also give me nice covered vestibules to put stuff out there instead on a dirt or grass etc...I also used it today as my sit pad or to lie down when having a hiking break...hope you see that and redo the video lol😂

Scandinavian here: a piece of polycro cut to the shape of my tent (45 grams) keps the tent floor against the ground dry and out of the mud. That's the only reason I use a footprint.

As others mentioned, primarily it is easier to clean a muddy footprint, but I also use it for more occasions:

The two main advantages for me are that it separates the mud/dust from the tent when packing it up, and that it allows the tent to be set up starting with the outer layer, which in the event of rain ensures that the inside stays dry. Unfortunately, here in France, even in midsummer, you have to be prepared for rain ._.

If you’re on muddy or dirty ground, you can roll your tent and fly up on top of the footprint, making it much easier and nicer for packing up. Then you can stuff your nasty muddy, wet footprint separately. I just use a thin piece of poly tarp, weighs very little, does the trick, and can be a handy piece of emergency equipment.

Lots of goat head stickers in the areas I camp at regularly. I’m not going to jeopardize the integrity of sleeping pad because a goat head pokes through my tent floor.

You make some great points and a lot of what you say sounds good. I do take issue with a couple of things though. First condensation. A lot of the reduced condensation claims I've seen have come from You Tubers in the UK. From memory they have been using Hilleberg tents that have ground sheets/foot prints that go under the tent AND vestibule area. Anecdotally when I have tried the same with my groundsheet of choice, An SOL emergency blanket that weighs only a few ounces and is a double use item, I get less condensation (not scientifically tested of course). My second issue is that I backpack a lot of the time in environments that require you to pitch on sand stone. I've worn through sections of my 100D-200D day pack by simply brushing across sandstone a couple of times. Brand new pack+ 5 or 6 feet of sandstone= hole in pack. I'm not sure 8+ hours of me tossing and turning on a 30D floor, directly on sandstone, won't have some negative impact, especially with my full weight on the fabric as opposed to simply brushing past the sandstone while hiking, which created holes. Obviously what I'm describing is pretty specific to backpackers in the Southwest, I assume. And clearly I've not done any scientific studies just my experience. Either way I enjoy and appreciate all of the work you do, I just wanted to bring up these two points.

Loved your videos and how you thoroughly test your theories. One thing I will say with footprints is that they help keep your tent clean. I went backpacking and it rained didn't have a footprint and my tent got muddy. Had to spend a lot of extra time cleaning it when I got home. When it rains is when I wish I had a footprint for sure

I LIKE A FOOTPRINT.

Good stuff. Not often I throw a tent up in conditions like you show, sandy and level. We primarily backpack in the Rocky mountains and the desert SW where we frequently are off trail and conditions are rocky and uneven. The footprint gives added protection and peace of mind but also is used for rainy conditions to allow a fly first tent setup/teardown. It’s worth the weight IMO…

I am using a Tiger Wall UL3 for my gf and I. We bring a footprint every time because it also allows us to setup a sun/rain shelter without having to put together the inside netting. Sure - I paid a pretty penny for it and it does take up some pack space, but the convenience and peace of mind is worth it. I think whether you need a footprint or not is also largely dependent on which region of the world you are pitching your tent. I mostly backpack in the Sierra and the sites tend to be rather rocky and scattered with broken pinecones.