Yea well it is supposed to be, but I don't think it's really very secure. The moment you lose it and someone gets it in their hands, your seed phrase is no longer yours.
I guess it could work if one bought at least three of them, and used them for divided seed phrases and gave each for a friend or relative for safe keeping. Or maybe put them in ground. But even that is not secure these days. Maybe a bank vault could do.