Has anyone ever recieved blotter where the back side has a pinkish red stain or tint to it? I've heard some people say that's a likely sign of an RC but they havn't been able to explain why. I asked the person I got the tabs for what it's from and he said it had to do with how it was laid but couldn't really elaborate. I'm planning on getting a reagent test just for the peace of mind, but I was just a little curious if anyone else here has seen similar blotter and if they know what causes it. Also, on a side note, about a month ago I got tabs that were the from a sheet with the same art from the same person but the back of the tabs was white. Is there anything used in laying tabs that could cause a color change after time after being exposed to light or air?