While some software exists to help editors in accurately casting off manuscripts, the process cannot be completely automated because only an experienced editor can foresee the many variables that can affect a book's page length  .
While some software exists to help editors in accurately casting off manuscripts, even an experienced editor often can't foresee the many variables that will affect a book's page length , some of which may not arise until the book is well into production .
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, some of which may not arise until the book is well into production