Infrared IFF

M1 Abrams tank firing calibration shot at Grafenwoehr Training Area, Germany, Oct. 1.

Saw this pic over at Military Photos dot net, and thought it was kind of cool. I mean, I like tanks (big, heavy, powerful machines, with big guns) and here we have a lance of fire shooting out to the right. But other than that, well nothing too special.
    Then someone asks what the brown panels are (you can see one on the back of the turret and one on the side) and the reply comes back that they are Infrared IFF (Identify Friend or Foe) devices that show up black on thermal imagers. They show up black because they are cooler. Whaaaaaa???? How can that be? They are just panels, no electronics, no internal mechanism, no refrigeration. This is just too weird, so I go wander down the rathole...

 

Seems a company called Cejay Engineering has come up with tape that has low emissivity in a select portion of the infrared portion of the electromagnetic spectrum. Emissivity tells you how much infrared energy an object radiates in relation to its temperature. For most stuff the emissivity level is relatively high, so the radiation corresponds well with the object's temperature. Shiny metals, not so much. Doing something as simple as painting a shiny metal surface, or spraying it with oil, can boost the amount of radiation coming from the object, and drastically alter it's appearance in a thermal imager. That's how you can raise it. How they can make this material have a lower level is a mystery.
 

This is a screen shot from a Cejay Engineering video (49 second mark). The black blobs in the center are some of these magic thermal panels
Here's some more curious pics.

Hot, non-stick frying pan:

The aluminum side of the hot pan appears cool (left) because it doesn’t emit efficiently and reflects the cooler surroundings. Flip the pan over and the non-stick side (right), being a much more efficient emitter, reveals how hot the pan really is.

Steel block:

Figure 3: Steel block, left side painted black.   Figure IR3: Corresponding thermal image of steel block.  

I'm hoping I'm not giving away any military secrets here, but then I found this stuff on the internet, so how secret can it be? The tape might be embargoed.