Useful information on what NOT to cut. http://atxhackerspace.org/wiki/Laser_Cutter_Materials?fbclid=IwAR1yC5H2vA8EGck_GnWu_dUmBwC88hNynbysyk01ZKK5UpumWdbw6d50GVs#NEVER_CUT_THESE_MATERIALS