Cut and dried actually has two related but somewhat different meanings:
CUT AND DRIED (or DRY) / CUT-AND-DRIED (or DRY) adjective: 1) prepared, arrange, or settled in advance; not needing much thought or discussion, readily resolved, having no loose ends or complexities <‘a cut-and-dried decision.’>. 2) lacking in originality or spontaneity, commonplace, routine, boring, perfunctory, hackneyed, run-of-the mill <‘a lecture that was cut-and-dried.’>
The expression first appeared in print in 1710 (see below), but the original theory that the allusion was to timber that had been cut to standard sizes and dried and which was for ready for use, as expressed by ‘Brewer’s Dictionary of Phrase and Fable’ and some others, is now believed to be incorrect and many sources don’t even mention it (OED, American Heritage Dictionary of Idioms, Picturesque Expressions, etc.).
Etymology: “Originally referring to herbs in the herbalists' shops [[which were cut and then dried before being sold]], as contrasted with growing herbs.” (Oxford English Dictionary). This origin led to the meaning of ready-made and lacking spontaneity, far from fresh, hackneyed and was first recorded in 1710 in a letter to a preacher in which the writer said, “Your Sermon was ready Cut and Dry'd.” The expression also came to mean ‘clear-cut’(not requiring much thought). By the time Swift used the phrase for hackneyed literary style in his poem ‘Betty the Grizette’ (1730) it was also fairly hackneyed itself: “Set of phrases, cut and dry, evermore thy tongue supply.”
Ken G – June 16, 2004