Which exhaust material is cooler to the touch?

[daveoner]

I heard that carbon fiber exhaust cans are cool to the touch- that they don't "burn" your leg if you touch 'em all day.
Is that true?
I am considering an aftermarket exhaust for my 03 SV650. Anyone have experience with any aftermarket dual exhaust for the SV?
I have seen some underseat exhausts systems by Ixil and GPR, but only on the internet. I read some stuff about Renegade, expensive. Most companies offer titanium, stainless and carbon fiber. If carbon fiber dissipates heat best or does not retain heat at all; that would be a pretty cool benefit.

[BuzZz]

Of all the common materials they make exhaust cans out of, carbon fiber would have the best insulating qualities. All the others are non-organic metals and so conduct heat pretty well.

I have heard of and seen pics of carbon fiber exhausts that have caught fire from the heat inside them. When they do light-up, I guess they burn like a M.F and are hard to put out. To be fair, these have been mostly on race bikes, pushing the edges of thermo-dynamics and being run hard. A street engine will not see such high exhaust temps without being seriously out of tune.