cut from whole cloth

Entirely fictional or utterly false; completely fabricated and not based on reality at all. A reference to tailors who would falsely advertise garments being made "out of whole cloth," when, in reality, they were pieced together from different cuts. To be honest, I don't believe a word he says—it sounds like it's cut from whole cloth to me.

A fabrication; untrue. From the mid-fifteenth century on, whole cloth meant a piece of cloth of full size, as opposed to one from which a portion had been cut. The term was used figuratively in various ways from the late sixteenth century on, and the current cliché came into use in the early 1800s. Lexicographer Charles Funk suggested that the turnaround came from the fact that some tailors deceived customers by using patched or pieced goods instead of a genuine full width of cloth. William Safire commented that by ironic transference the fabrication (cloth) was treated as another kind of fabrication (a lie). An early appearance in print came in Thomas Chandler Haliburton’s The Clockmaker (1840): “All that talk about her temper was made out of whole cloth. . . . What a fib!”