When I wash a glass or cup, I run my fingertips all around the upper edges; where the vessel meets the lips. I am feeling for tiny invisible islands, archipelagoes of stasis, insuring that where the circle meets the lips, it is certainly clean. Fingertips are sensitive. Occasionally, however, there is a micro-crack on the rim of a crystal cup. It cuts my fingerprint, painfully. But your lips are spared…