>You will get the best effectiveness with aluminum as a material. It is very light, and reflects the most heat back towards your pot, of the common materials. Better than steel, better than titanium.
Really! This is news to me. I thought heat reflectivity was more a function of the finish. For example, that a shiny surface would work better in theory than, for example, flat-black stippled surface, etc. I was unaware that the metal of the shield had anything to do with its effectiveness as a reflector. I'm aware that aluminum conducts heat better than steel or titanium, but it's surprising to me to learn it's a better reflector!
I recollect someone saying that titanium has been used as a heat shield on aircraft or spacecraft, and that would make me think it would be good at reflecting (and dissipating) heat away from its surface.
Now, if you consider a shield to be a heat SINK, then I can see aluminum (or copper) being superior. In theory. The aluminum we use for a wind screen is pretty darned thin and would not act as much of a heat sink.
Interesting. Not arguing, just trying to understand. The above quote puts in doubt my understanding of heat reflection.