These are referred to as safety threads. When you hold up US dollars, to the light, the security threads need to appear to be a Section of the Notice, versus becoming printed on it. Also, consider tearing the bill in 50 percent; if it rips easily, then it’s likely copyright. https://ketaminetherapynearme32973.blogozz.com/32693168/the-smart-trick-of-copyright-one-dollar-bills-that-no-one-is-discussing