# Blue pencil (editing)

A blue pencil, also known as a checking pencil, is a two-color pencil traditionally used by an editor to correct a written copy. The blue end is typically Prussian blue, and the red end is typically a warm vermilion red. They are most often half red and half blue, but some are 70% red and 30% blue. An editor-in-chief would use a blue colored pencil to make proofreading marks and final notes on manuscripts before sending it to be typeset and published. The pencils and their blue excisions became associated with the editing process and editorial oversight.
   Of course it takes skill to be a poet! But an editor? A pair of shears, a blue pencil, and a paste-pot!
Since the introduction of desktop publishing, editing is typically done on computer files and without literal blue pencils. They continue to be used in the Japanese newspaper industry and elementary schools in parts of Europe. A different type of non-photo blue pencil is used by some comics artists for different purposes.

## History

Neither the exact date that blue pencils were introduced nor the details of how they became an editing standard are certain. Blue checking pencils were sold in the United States during the nineteenth century. Eberhard Faber offered a range of two-color pencils by 1873. Multinational manufacturer AW Faber sold wood and mechanical blue pencils in the late 1800s. By 1888, "blue pencil" was being used as a synonym for "edit" or "censor". During World War II, bi-color pencils were used to mark troop positions on maps.

### Censorship

Blue pencils became associated with editorial control and with censorship. Under the Estado Novo in Portugal the "blue pencil" became a metaphor as editors would use blue pencils to censor out portions of works rather than banning the entire text. In parts of Africa, the "blue pencil" became a metaphor for the censorship and banning of entire books.

## Post pencils

In parts of Europe, blue pencils are used in elementary schools. In Hungary, children are taught the difference between uppercase and lowercase by writing the cases in different colors. In Germany, they are used to write separate syllables and numerical digits in alternating colors. In Italian classrooms, they are used to mark separate types of errors.
The blue pencils for schoolchildren are sold as "copying pencils" or "post pencils". In early twentieth-century Germany, blue pencils were used to mark postal routes. Checking pencils have been called "post pencils" as early as 1909 in Europe.

## Non-photo blue pencils

In the production of comic books, blue pencils have a different but overlapping usage. American comic books are typically illustrated by multiple specialists. The penciller does the initial drawing, the inker brushes black ink over the pencil art, and the colorist adds colors to photocopies or digital scans of the inked art. Some pencillers have worked with non-photo blue pencils. These cyan colored pencils leave marks that orthochromatic film for offset lithography does not capture, and digital scanners can filter that out.
Editors used the same cyan pencils to add notes to art before publishing, like editors in the broader publishing industry. Original pencil art for comics was initially treated "as a means to an end rather than as an object of intrinsic value" but has come to be viewed as valuable art. The un-inked pencil drawings provide a more detailed representation of the original illustrators' work and have blue-pencil notes that sometimes go beyond technical issues to address ideas discussed in the creative process but never used in finished comic books.
For similar reasons, some illustrators use red pencils that can be filtered out with xerography or digital scanners. Comic book artist Rob Guillory used checking pencils to illustrate Chew and Farmhand.

## Legal doctrine

The blue pencil doctrine is a legal concept in common law countries where a court finds that portions of a contract are void or unenforceable, but other portions are enforceable. It derives its name from the court's ability to edit a written contract, similar to how an editor-in-chief would edit a manuscript.
The blue pencil rule allows the legally valid enforceable provisions of the contract to stand despite the nullification of the legally void unenforceable provisions. However, the revised version must represent the original meaning. The rule may not be invoked, for example, to delete the word "not" and thereby change a negative to a positive.