http://www.wima.de/navig/tech.htm http://www.wima.de/characteristics.htm http://www.wima.de/navig/pr.htm http://www.wima.de/navig/spotlight.htm http://www.diyaudio.com/forums/showthread.php?threadid=29427 www.circuitsonline.netCondensator typen - Forum - Circuits Onlinehttp://www.circuitsonline.net/forum/view/28131 http://www6.head-fi.org/forums/showthread.php?t=2718 http://www.selectronic.fr/famille.asp?fam_ref=05 MKT/MKS ( polyester ), MKC ( polycarbonate ), MKP/KP ( polypropylene ), KS ( Styroflex/polystyrene ). PTFE/Teflon is one of the best but hard to find and expensive. There are subvariants like FKP pulse caps which are a polypropylene variant.