In 1910 at a séance in Grenoble, France the apport medium Charles Bailey produced two live birds in the séance room. Bailey was unaware that the dealer he had bought the birds from was present in the séance and he was exposed as a fraud. The psychical researcher Eric Dingwall observed the medium Bert Reese in New York and claimed to have discovered his billet reading tricks. The most detailed account at exposing his tricks (with diagrams) was by the magician Theodore Annemann.
In the late 19th century, the fraudulent methods of spirit photographers such as David Duguid and Edward Wyllie were revealed by psychical researchers. Hereward Carrington documented various methods (with diagrams) how the medium would manipulate the plates before, during, and after the séance to produce spirit forms. The ectoplasm materializations of the French medium Eva Carrière were exposed as fraudulent. The fake ectoplasm of Carrière was made of cut-out paper faces from newspapers and magazines on which fold marks could sometimes be seen from the photographs. Cut out faces that she used included Woodrow Wilson, King Ferdinand of Bulgaria, French president Raymond Poincaré and the actress Mona Delza.