Wiktionary
n. 1 (context printing English) The inverted image of an original proof. 2 (context logic English) A proof that contradicts a given statement.
Wikipedia
In engraving, a counterproof is a print taken off from another just printed, which, by being passed through the press, gives a copy in reverse, and of course in the same position as that of the plate from which the first was printed, the object being to enable the engraver to inspect the state of the plate.
Counterproofing was used to produce the finest quality copperplate printing; the second print consisted of delicate lines, and lacked the beveled impressions seen in the original print.
To counter-prove is also to pass a design in black lead or red chalk through the press, after having moistened with a sponge both that and the paper on which the counterproof is to be taken.
Usage examples of "counterproof".
But with Chapter 13 the intention to convince drives out the creative intention to state, and with but one intermission— when the hedgehog leads Arthur to a hill in the west-country, where he sits looking at his sleeping kingdom under the moon and is reconciled to the bad because of the good—the book clatters on like a factory with analysis, proof and counterproof, exhortation, demonstration, explanation, historical examples, parables from nature—even the hedgehog talks too much.