Why does a blue paper towel turn yellow in acid?

Without knowing the molecular structure of the blue pigment, I can't give a definite answer. But let's assume that, for a mass-produced product, it is a pigment from some plant source. The two most common kinds of plant pigments are anthocyanins, ... read more

Without knowing the molecular structure of the blue pigment, I can't give a definite answer. But let's assume that, for a mass-produced product, it is a pigment from some plant source. read more

Write a message on a piece of white paper using a paintbrush or q-tip, dipping in the ink frequently. Let the message dry. Turn on the toaster and carefully hold your paper over it. read more