Why Is There White Paint On Port Bottles
Some Ports have a splash of white paint or chalk on the bottle. This white mark is also called a 'splash mark' and is added to the uppermost side of the bottle and is there show which way up it was cellared.
You too should then store your Port Wine with the splash of white paint uppermost. This allows the sediment to settle uniformly in one place. Then when Decanting The Port keep this mark uppermost to minimise the amount of sediment poured.