PMMA http://www.plasticseurope.org/what-is-plastic.../pmma.aspx http://pslc.ws/mactest/pmma.htm Melting point 160 °C (320 °F; 433 K)[ 3] https://en.wikipedia.org/wiki/Poly(methyl_methacrylate) ......wasn't that a metric met initially w/QDX tm, (160 deg C)? QDX tm