1996 version of the security thread of the hundred-dollar bill will emit pink light under ultraviolet radiation. The security thread of the 2004 edition hundred-dollar bill will emit green fluorescence under ultraviolet radiation. Starting from 1990, a safety thread made of polyester polymer called Myra was added to the paper (left). There are dollar symbols and denomination figures on the security line, which can be seen clearly in perspective. The ink on the front of the dollar is black, slightly dark and slightly gray, and the back is green.