Sorry that I come up with this again but right now my lab is just full of crazy folks with all kind of problems and whenever I have a sec. to spare another thought comes up to me. What I wanted to suggest is an approach we tried when we saw the problem with Polycarbonate. We covered the material with a transparent Tungsten Carbide layer ( a Swiss watch manufacturer has a unit where they produce their inscratchable watches by covering the glass with it ). Nowadays thin diamond layers can be produced and one can also buy sunglasses with a transparent metal cover. Unfortunately, due to cost reasons, the research in the field was dismissed. Just a thought Regards Guenter ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################