I noticed this thing on a batch of 12 troll torsos I bought off Bricklink some months ago. Now I know they probably came from the Giant Chess (as the BP wasn't available back then).
This really bothers me since I specifically bought these torsos to make these guys
. Now that non-shiny brownish print just doesn't go at all with the copper axe heads and shield accents... (the ones in the picture are the "normal" shiny ones).
And yes, I do feel a difference in material, too. The plastic feels somehow "lighter", less dense. I've noticed the same thing with the Pirate fig from the impulse set (head & torso).