As I rushed out of the office last Friday to beat rush hour traffic and to catch a flight PDX bound so I can attend the loveliest wedding ever. I took one last sip of coffee for the extra kick I needed to make it through the night! I left a shallow glaze of coffee in my cup! To my pleasant surprise- Monday morning I'm greeted with this pretty darkly stained @ the bottom of my cup. The gradation between the dark and the light areas reflecting on the white ceramic cup is quite pretty I'm hesitant to wash it.