carbon paper

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A lightweight paper coated on one side with a dark waxy pigment, placed between two sheets of blank paper so that the bottom sheet will receive a copy of what is typed or written on the top sheet.

Century Dictionary and Cyclopedia

1. n. Paper faced with carbon or lampblack: used between two sheets of paper for the purpose of reproducing upon the lower sheet anything which may be written or drawn upon the upper sheet, or printed upon it by a type-writer.

Wiktionary

1. n. A sheet of paper with one of the faces impregnated with carbon, used to make carbon copies.

GNU Webster's 1913

1. n. a thin type of paper coated with a dark-colored waxy substance which can be transferred to another sheet of paper underneath it by pressing on the carbon paper. It is used by placing a sheet between two sheets of ordinary writing paper, and then writing or typing on the top sheet, by which process a copy of the writing or typing is transferred to the second sheet below, making a copy without the need for writing or typing a second time. Multiple sheets may be used, with a carbon paper placed above each plain paper to which an impression is to be transferred. In 1997 such paper was still used, particularly to make multiple copies of filled-in purchase invoice forms, but in most applications this technique has been superseded by the more faithful xerographic reproduction and computerized printing processes.

WordNet 3.0

1. n. a thin paper coated on one side with a dark waxy substance (often containing carbon); used to transfer characters from the original to an under sheet of paper