The gallery had paid a premium for an authentic photograph of a rare bird on a wire. (authentic: genuine, bona fide, real) A second print showed the same bird on a gate. One picture was a fabrication. (fabrication: invention, falsehood, fiction) The dealer offered to avouch the authenticity of both, but he would not aver that he had seen either negative. (avouch: affirm, avow, assert; aver: assert, affirm, declare)
A retired printer knew the defect in the old enlarger. It would diffuse a little light into one corner, a blemish that could diminish in a later copy. (diffuse: scatter, spread, disperse; diminish: decrease, lessen, reduce) The attendant regarded such a diminution as too insignificant to matter. (diminution: reduction, decrease, lessening; insignificant: unimportant, negligible, trivial) The printer disagreed. A counterfeit need not subtract an entire bird. An extra scratch was sufficient to discredit the claim that both prints came straight from the same negative. (discredit: undermine, disprove, cast doubt on)
Under the magnifier the feet were identical, down to an improbable bend in one claw. (improbable: unlikely, implausible, doubtful) The printer took a third picture from his wallet. The bird sat on his daughter's birthday cake. It was sugar. The daughter, now the gallery treasurer, agreed to donate the model. The dealer quietly bought the cake photograph. It was the only one whose story he could prove.