Sometimes the most interesting part of electron microscopy is the carbon tape.
It’s basically just conductive tape, and we use it to stick our samples to their little metal holders before we put them in the microscope. To the eye, it’s jet black and lightly textured. Under the electron microscope, it’s always weirdly organic-looking and spectacular, like some kind of strange life-form oozing over the otherwise clean metal.
I end up having to look at carbon tape at the beginning of almost every electron microscope session, usually to make sure the microscope’s focusing properly, and I always am secretly very pleased to do so.