Goodbye mismatched paperbacks

I've been getting three at a time from my SIL, for my birthday and Xmas. Up to Fifth Elephant now. Can't remember exactly where it happened, but a few books ago they stopped including the bookmark ribbon. Apparently at that point in the series they switched printers and the ribbon got excluded. Unreasonably bothered by it, going to learn how to add them in.

The Sam Vimes theory of discworld novels.