A large room in a monastery reserved for the use of the scribes or copyists of the community.
When no special room was devoted to this purpose separate cells or studies called "carrels" were made in the cloister, each scribe having a window and a desk to himself.
The scriptorium was under the care of the precentor, or one of his assistants called the armarius, who provided all the requisites peeded by the scribes, such as ink, parchment, pens.
Rules of the scriptorium varied in different monasteries, but artificial light was everywhere forbidden for fear of injury to the manuscripts, and silence was always enforced.
Often the scriptorium of a monastery developed some peculiarities of writing which were perpetuated and are of great value in ascertaining the source from which a manuscript comes.
New Catholic Dictionary