Every medieval monastery needed a stock of working copies of bibles, Psalters, and missals for the liturgical life of the community; they also needed copies of the Rule, penitentials, and, indeed, secular documents such as deeds and letters in their dealings with the world. For religious study multiple copies of commentaries on the scriptures, lives of the saints, and the writings of the early Church Fathers were made. The monastery library and school needed texts and scholarly glosses. Psalters were the primers for the novices. Copies had to be handwritten in the scriptorium or medieval monastic secretariat. The first call on the scribes in the scriptorium, usually situated adjacent to the library, was the reproduction of books for the services in choir and the readings in the refectory. Some scriptoria (like that at Armagh—which, according to the Annals of Tigernach, escaped destruction in the great fire of 1020) acquired a reputation for excellent calligraphy and beautiful illuminations and royal patrons paid handsomely for de luxe products.
The work of scribes, copisti, and illuminators to produce legible and correct copies required not only a scholarly mastery of reading and interpreting of the texts called exemplars (borrowed from neighbouring monasteries) but also great skills in the art and craft of writing in the distinctive insular majuscule and minuscule Irish hands. Animal skins for vellum and parchment were expensive in the seventh and eighth centuries, hence the use of minuscule to get more writing onto a page and likewise the use of palimpsests, that is, previously used parchments, showing over-writing, marginal notes, and the interlinear glosses much favoured by Irish scribes. Scraping, curing, and dyeing of vellum was an important activity in the preparation of writing materials in the scriptorium, as was the making of inks—mainly black, red, yellow, and purple; this last, procured from a particular sea-shell. So too was the cutting of quills sliced off in a chisel edge to produce the distinctive thick down strokes and thin horizontal line of insular minuscule script. Perhaps the finest early example of this script in Irish is that of Ferdomnach who penned the Book of Armagh (807). The development of minusculeor lower case letterforms was arguably the most important Irish contribution to written language in Western Europe. Until the rise of the university stationers in the thirteenth century monastic scriptoria had a monopoly of book production.
Often a copyist, pure and simple, made errors and copied errors of syntax and grammar and of fact—but a scribe with better latin and sounder scholarship corrected copy. Irish trained scribes are to be found not just in Northumbrian scriptoria but also in those of Scotland, Anglo-Saxon England, and naturally in the original Columban monasteries of Europe. The technicalities of distinguishing Northumbrian, Anglo-Saxon, and Irish scripts are complex and have led to much controversy, for example, over the date, place, and origin of the celebrated Book of Kells. While the majority of monastic scribes could copy texts and documents for practical usage, few could have been skilled enough artists to execute the illuminated art treasures which the Irish monasteries gave the world in such plenitude of artistry as in the Books of Durrow, Kells, Armagh, and Lindisfarne, and indeed, the Latin Gospel Books of Echternach, (in the Bibliotheque Nationale in Paris-latin Ms 9389), Durham, and Lichfield, all of which display a marriage of calligraphy and illumination reaching its full maturity in the case of Kells.
After the twelfth-century manuscripts were no longer produced solely for monastic usage, books were executed for lay patrons by secular professional scribes from the learned families. The "Golden Age" of the Gospel manuscripts, the illuminated service books and the book shrines of the Celtic saints, was largely the product of Irish monastic scriptoria, ensuring them a unique place in the history of western European civilization.
