JoshuaNet

The Jews had a tremendous reverence for Scripture. Their copying procedure were very detailed and meticulous. Samuel Davidson provides a listing of the regulations followed by the scribes: [1]

A synagogue roll must be written on the skins of clean animals,
prepared for the particular use of the synagogue by a Jew.
These must be fastened together with strings taken from certain clean animals.
Each skin must contain a certain number of columns, equal throughout the entire codex.
The length of each column must not extend over less than forty-eight or more than sixty lines; and the breadth must consist of thirty letters.
The whole copy must be first lined; and if three words be written without a line, it is worthless.
The ink should be black, neither red, green, nor any other color, and be prepared according to a definite recipe.
An authentic copy must be from an exemplar, from which the transcriber ought not in the least deviate.
No word or letter, not even a yod, must be written from memory, the scribe not having looked at the codex before him
Between every consonant the space of a hair or thread must intervene;
Between every new ... section, the breadth of nine consonants;
Between every book, three lines.
The fifth book of Moses must terminate exactly with a line; but the rest need not do so.
Besides this, the copyist must sit in full Jewish dress,
Wash his whole body,
Not begin to write the name of God with a pen newly dipped in ink, [2]
And should a king address him while writing that name he must take no notice of him.

Footnotes:
[1] Samuel Davidson, “The Hebrew Text of the Old Testament,” 2nd ed., London: Samuel Bagster and Sons, 1859, p. 89 as shown in “What Everyone Needs To Know About The Bible,” by Don Stewart, Dart Press, p. 62.
[2] Meaning that a new pen would be used every time the name of God was written, as opposed to a used pen newly dipped in ink.