Backed by $NIGHT
A share of every mint, out of circulation, written into the contract.
A backed collection is priced in $NIGHT, and a share of every mint (chosen by you at launch, up to all of it) goes straight to the dead address in the same transaction. The rest reaches your payout address as it always does.
Why it must be $NIGHT
The factory refuses a backed collection priced in anything else, and that restriction is the whole feature. Routing a share of a stablecoin to a dead address destroys real value and removes nothing from anywhere, while the page says the same reassuring sentence either way.
Why there is no buyback
A buyback is machinery for turning demand in one currency into demand for another. Pricing the mint in $NIGHT skips the machinery: somebody has to go and buy the token to mint, which is real demand, and the share removed is supply that does not come back.
A swap inside the mint transaction would also be a mint that can fail because a pool was thin at that second. Nothing here can revert for a reason that has nothing to do with the collector.
It is fixed
backingBps is set in the deployment transaction and there is no function that changes it, not for you, and not for us. It is printed on the mint page as a promise to two parties at once, and a promise with a setter is a suggestion.
Until setNight names the fee token, the factory has nothing to compare the mint currency against and refuses backed collections outright. The form shows the option and explains why it is not offered yet, rather than handing you a button that reverts.