A head-pressure-variant, self-healing, anti-liquid-leak coating for the outside of an upright wall in a liquid container. This coating possesses a thickness which varies from smaller toward larger advancing downwardly along a coated container wall. Preferred embodiments of the coating include: (a) one whose overall thickness varies in a linear way; (b) another whose thickness varies in a staged/stepped manner; and (c) a third whose thickness varies in a smooth, non-linear way. In all embodiments, the coating includes plural layers having interlayer-thickness relationships which are the same throughout the coating.