Triboluminescence is nothing new - it's been known for decades that if you quickly pull some tape off a roll, you can see sparks. (HINT: if you are trying this a home, do it in a dark room with you eyes adjusted to the darkness.) But now some researchers have found that you can even generate x-rays from this simple act.
Since they correlated it to the stick-slip phenomenon, this would predict that masking tape (tan, not blue) and even duct tape would be a stronger source. (Stick-slip is an uneveness in the peeling. As you pull on the tape, it doesn't peel until a critical amount of energy is stored in the system and then it lets go suddenly, starting the cycle all over again. This also produces noise. Noisy tapes have lots of stick-slip.)