Putting pages back in the right order
Reordering rewrites the sequence of pages without touching what is on them. The most common reason is a scanner: a double-sided document fed through a single-sided feeder comes out as all the fronts followed by all the backs, and the pages need interleaving before it reads correctly.
As with the other page operations, nothing is re-encoded — the file you get is the same pages in a different order, at the same size and quality.
- Cross-references do not follow
- A contents page listing “Section 3 .... page 12” still says page 12 after you move things. Reordering moves pages, not the words printed on them.
- Check the result end to end
- An off-by-one in an interleave is easy to make and easy to miss, because every page individually looks right.