These are typically identified as security threads. Any time you hold up US dollars, to The sunshine, the safety threads need to seem like a part of the note, versus being printed on it. Also, try tearing the bill in fifty percent; if it rips conveniently, then it’s probably copyright. https://evrenzo-roxadustat97048.blogvivi.com/36089412/the-smart-trick-of-copyright-one-dollar-bills-that-no-one-is-discussing