Rather than pretending to know more than I do, I recommend that you look at Enjoy the Music website and Audioholics for good discussions of wire. That includes the shielding, inductance, capacitance and resistance. I likewise will shortly buy wire and supplies to make interconnects. I am still deciding if I want a coax style with a center conductor, or a twisted wire type. The short answer is that Teflon is second only to air as a dialectric and this reduces capacitance. Apparently, many commercial interconnects use PVC, but Teflon is superior as a dialectric. Whether this is significant to the sound is matter of debate. TNT-Audio also has good discussions about the electrical properties of materials in the production of audio wires, including a few good DIY projects. Good luck!