[kragen]

this is a great paper, thanks

a thing to keep in mind with research papers is that in many cases they're concerned with finding how to get the largest effect, or demonstrate the effect in a way that's most clearly due to the reasons they claim and not some experimental error, or measure the effect most precisely, and only in rare cases are they concerned with how to get the effect most cheaply, a consideration which conflicts with the others

there are a lot of cheap materials that are transparent in the thermal infrared, like ldpe, potassium chloride, sodium chloride, silicon, and rock crystal. they're mostly a pain in one way or another (not that i have any experience with this)