Carbon copy

In the past, a carbon copy was the under-copy of a document created when carbon paper was placed between the original and the under-copy during the production of a document. With the advent of email, the abbreviations cc or bcc (blind carbon copy) have also come to refer to sending copies of an electronic message to recipients other than the addressee.

Nowadays "carbon copy" is often used metaphorically to refer simply to an exact copy. It is not to be confused with the carbon print family of photographic reproduction processes.

A sheet of carbon paper is placed between two or more sheets of paper. The pressure applied by the writing implement (pen, pencil, typewriter or impact printer) to the top sheet causes pigment from the carbon paper to make a similar mark on the copy sheet(s). More than one copy can be made by stacking several sheets with carbon paper between each pair. Four or five copies is a practical limit. The top sheet is the original and each of the additional sheets is called a carbon copy.

The use of carbon copies declined with the advent of and electronic document creation and distribution (word processing). Carbon copies are still sometimes used in special applications: for example, in manual receipt books which have a multiple-use sheet of carbon paper supplied, so that the user can keep an exact copy of each receipt issued, although even here carbonless copy paper is often used to the same effect.

It is still common for a business letter to include, at the end, a list of names preceded by the abbreviation "CC", indicating that the named persons are to receive copies of the letter, even though carbon paper is no longer used to make the copies.

An alternative etymology is that "c:" was used for copy and "cc:" indicates the plural, just as "p." means page and "pp." means pages. This alternative etymology explains the frequent usage of "c:" when only one recipient is listed, while "cc:" is used for two or more recipients of the copies. This etymology can also explain why, even originally, "cc:" was used to list recipients who received typed copies and not necessarily carbon copies.

The term "carbon copy" can be used in reference to anything that was a near duplicate of an original ("...and you want to turn him into a carbon copy of every fourth-rate conformist in this frightened land!", Heinlein, Stranger in a Strange Land).

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Wikipedia