|>>|| No. 63757
>Because in the old days they weren't. They came unsalted and you had to find the pinch of salt in a twist of paper, fish it out and sprinkle the contents over the crisps. Smith's Crisps were the leading brand and when Walker's came along their main selling point was that they were 'ready salted' and you didn't have to fiddle with the blue bag any more.
It obviously is along the same lines as something that is ready made. You wouldn't substitute it for already made would you?