I acquired many years ago, probably from a fair or garage sale, a copy of the seventh edition of 'The Dictionary Of Photography', by E. J. Wall F.R.P.S. publ: Hazell,Watson, & Viney, Ltd. 1897. I was perusing the volume last evening and realised the pamphlet contained loosely within the volume had two images, one very faint, a man and a woman, printed on it. The pamphlet is an instruction sheet printed by The Autotype Company, London dated March 1892. The image of the woman appears to be a form of dot print. The image of the man appears to have been rendered with brush strokes.I wondered if they may have been printed with carbon tissue but I am not familiar with the process.