The primary method of copying manuscripts was by an individual scribe or by the succession of individual scribes. In doing so, an exemplar document from an archive or any document from a previous generation would sit on a table alongside the blank pages, and the scribe would copy the document. It may sound simple on the surface, but transcribing entire volumes of text for hours on end with nothing but candlelight can be taxing on the mind, the eyes, and the hands.
Scribes can be categorized by the nature of their document transcriptions and the techniques they use to copy works.
Professional
A professional scribe is someone who makes a career from copying manuscripts. Such an individual is fluent in the language of the document and takes care in alignment of text and clear handwriting.
He or she copies text by the letter or by small groups of letters. The content of the document is not as important as the text itself, since the scribe guarantees that the original meaning stays true in the copy, anyways.
At the foot of the document, he or she will notate the number of lines transcribed, since professional scribes were paid by the line. Ancient Jewish scribes went a step further and actually counted the number of letters on each page of the original manuscript and the new manuscript and would reject the copied page if there was any discrepancy.
An example of a professionally-transcribed manuscript of the New Testament would be the collection of Pauline epistles (Papyrus 46) housed at the University of Michigan in Ann Arbor and the Chester Beatty collection in Dublin, Ireland, as the end of each book contains line notations.
Documentary
Documentary scribes (and literary documentary scribes) are semi-professional. Such an individual may transcribe manuscripts part-time and have additional work at other times.
This classification is more common when an exact reproduction may not be deemed important, as long as the meaning is held. They may try to correct spelling errors or grammatical syntax. Literary works, like those by Homer or Socrates would be transcribed by such an individual. Additionally, the Book of Acts was copied using these scribes before it was canonized into the New Testament in the early 2nd century.
A documentary scribe may copy verbatim (word for word) or by groups of words, so textual variants are more likely over successive generations. Many New Testament manuscripts were produced in such a manner by ancient churches.
Amateur
An amateur scribe is someone with no formal training at transcribing documents.
Such a person will most likely copy manuscripts by entire sentences or thoughts. Documents between successive generations will considerably vary. Many New Testament manuscripts from ancient churches have such manuscripts in their "graveyard" storerooms.
These scribes may not even be fluent in the source document's language - or even its alphabet - so handwriting can be fair to poor. They may not even check their work or allow margin notes (from documents used by priests in sermons) or mistakes to creep into the copies unchecked.
By @HullBreach
