The transference of patterns printed or indented on a sheet of paper to a plastic surface

Experiments have been made in which the image of Xerox-letters printed on a sheet of paper is transferred to a sheet of plastic and developed by dusting. The sheet of paper is sandwiched between two sheets of plastic, which are pressed between two flat metal plates by a mechanical press. After removing the pressure, the sheet of plastic facing the letter-printed surface of the sheet of paper is separated or torn from the paper using electrically insulated forceps. Then by sifting fine alumina powder onto the plastic surface, a dust figure can be obtained. This figure shows the transcribed letters corresponding to the original Xerox-letter on the sheet of paper.By this method, indented letters, or letters drawn with ink on a sheet of paper, or a fingerprint impressed on a sheet of paper can be transcribed onto the surface of a sheet of plastic.