What happened with paper (or plastic?) money with thin golden threads/particles in them issued in one of US states?

At least that was a kind of decent idea, when people really have gold they own in their hands.

As for that "backed by gold" something, there is a catch - to make it really work, they have to somehow allow every single user to easily check in person that at any give moment amount of gold in government storage is equal to amount in issued notes of any kind.

Otherwise there is no any difference with any other printed money. There always will be too small amount of people who will want to get their physical gold, so they will be able to issue much more notes into circulation than amount of gold they have. Even if those who establish that will be good honest guys, which is already questionable, those who come later could be usual greedy bastards.

That thing with gold backed notes already was the case in the past for nearly any currency in the world and we all know how it ended everywhere. What will prevent the same fate of that Texas new money?

That gold-filled notes I mentioned at the beginning was much more honest and reliable idea of making real sound money.