What's a thermal masking material? Tin foil?
Apparently the stuff Bruce Wayne sprays on the bat suit in BB was to help mask his thermal image. From Wikipedia 'The armor was then coated with a black latex material for camouflage and to dampen Bruce's heat signature, making him difficult to detect with night-vision equipment.' Not canon, I know.
Too Much Fun wrote:
There shouldn't be any doubt that his white face was not permanent, since there's that brief shot of him without any make-up at all when he's in disguise as a police man. Also, you can clearly see that some of the paint has come off during his interrogation scene.
Well, when I saw the film I assumed he'd used flesh coloured make up to disguise himself as a police man, much like Jack Nicholson in the Tim Burton film. I take your point on the interrogation scene though.