US Patent 9528862 Flame resistant fabric with tracing yarns

A flame resistant fabric with tracing yarns includes a flame resistant fabric with a first non-tracing yarn, and a second tracing yarn. The first non-tracing yarn and/or the second tracing yarn include flame resistant fibers being selected from the group consisting of inherently flame resistant fibers and treated fibers. When the flame resistant fabric is exposed to heat, flames, long-term excessive UV light, or the like, the first non-tracing yarn is adapted to hold its color and the second tracing yarn is adapted to change colors.