Hmm, daily contacts (at least all the ones I've tried - and I've tried many) are very different from two week ones, so is this a tricky way to say that these tubes are very different indeed? :foo:

To make them harder to patch (and to sell more tubes).

That is what I've found. My interpretation is that the smaller tubes tend to stretch more and pull open the holes... thus all the air leaks out quickly.

On the other hand, the larger tubes tend to not open the holes, and thus one is more likely to be able to pump up the tire and limp back home.

I installed Michelin Airstop A1 tubes into new tires about a month ago, and did not see any mold lines.

No, I was not trying to be tricky. I was under the impression that long ago when daily wear contact lenses first came out, they were the same as the weekly / monthly ones, and when the government / FTC found out, the industry denied misleading consumers and argued that it was selling convenience. But I am unable to find a citation for that now.