Dunno how many people here remember when spark wire was just that: wire.  But it was electrically noisy.  So it got replaced by carbon impregnated fabric, which has rather high resistance (a cheap way to damp the "noise").

Another way to suppress the "noise" is to wrap the wire (many turns, closely spaced) around an insulating core, which creates an inductive impedance, which accomplishes the same goal but readily passes spark current.  AFAIK, "MAGNECORE" was the first to explore this method, but several companies offer a similar product now.  According to some sources, the core material can make a large difference in the inductive effectiveness.  Therefore, I'd recommend
MAGNECORE.
 

-- 
Best Regards,
Dale_R (who has no financial interest in Magnecore)
Cozy MKIV #497

On 1/12/2013 7:21 AM, Bill Bradburry wrote: