Blackened Sales Receipts and Glowing Scotch Tape.?

I was in my room last night with the door shut and the lights off and the blinds closed, playing around with some film and old cameras. I cut up a roll of film, and I was going to tape it inside the camera. I took a roll of scotch tape, and pulled a piece off, and lo and behold, I saw light. At first I thought there was someplace where light was getting in my dark room, and I had moved the tape in front of the light source, which reflected on the tape. But after a look around I couldn’t find any place where light was getting in. So I continued. I pulled another piece of tape off, and I saw light again! I figured it was just a hallucination, but the next time I took a piece of tape I watched it, and it glowed. It was a greenish, eerie sort of glow, produced right where the tape comes off of the roll whenever I pulled at it.
Why on earth does this happen?

After I was done with the cameras for the night I went downstairs and sat by the wood burning stove. The pyro that I am, I naturally started looking through my pockets for something to burn. I found a sales receipt from Stop and Shop. I tore off a corner of the receipt and placed it on top of the stove, and watched it start to blacken. I picked it up after it was sufficiently darkened, but to my surprise, the other side was still white! I tried it with the rest of the receipt. Only the side with the printing on it changed color. It wasn’t burning, as I initially thought. There must have been some chemical reaction going on with whatever kind of coating is on the surface of the receipt.
What is on sales receipts that causes the one side to turn black when heated?