Before the introduction of printing into Europe, and its application to the production of books, the Librarii or writers of books, in Rome, were a regular company who had several immunities: their business was a trade, and they were regulated by certain laws.
Besides these writers of books, there were artists whose profession was to ornament and paint manuscripts, who were called Illuminators; the writers of books first finished their part, and the illuminators embellished them with ornamented letters and paintings. We frequently find blanks left in manuscripts for the illuminators which were never filled up. Some of the an client manuscripts are gilt and burnished in a style superior to later times. Their colours were excellent, and their skill in preparing them was very great.
This practice, of introducing ornaments, drawings, emblematical figures, and even portraits into manuscripts, is of great antiquity. Varro wrote the lives of seven hundred illustrious Romans, which he enriched with their portraits, as Pliny attests in his Natural History. Pomponius Atticus, the friend of Cicero, was the author of a work on the actions of the great men amongst the Romans, which he ornamented with their portraits, as appears in his life by Cornelius Nepos; but these have not been transmitted to posterity.
However there are many precious documents remaining, which exhibit the advancement and decline of the arts in different ages and countries. These inestimable paintings and illuminations, display the manners, customs, habits, ecclesiastical, civil, and military, weapons and instruments of war, utensils and architecture of the ancients; they are of the greatest use in illustrating many important facts, relating to the history of the times in which they were executed. In these treasures of antiquity are preserved a great number of specimens of Grecian and Roman art, which were executed before the arts and sciences fell into neglect and contempt. The manuscripts containing these specimens, form a valuable part of the riches preserved in the principal libraries of Europe. The Royal, Cottonian, and Harleian libraries, as also those in the two Universities in England, the Vatican at Rome, the Imperial at Vienna, the Royal at Paris, St. Mark's at Venice, and many others.
When the art of printing was first applied in Europe to the production of books, they were in imitation of, and sold as, manuscripts; and blanks were left at the commencement of the respective divisions of the work, for the illuminator to fill in with the proper letters, and ornaments, as was usual in manuscripts, and so close was the imitation that, even in our own time, it has required the assistance of a chemical test to ascertain which was manuscript and which was printed.
When the secret of printing was divulged, and the deception could not be continued, ornamental letters of a large size were introduced, and printed with two colours, generally red and blue, the letter being of one colour, and flourishes, extending the whole length of the page, in the other, so as to have the appearance of being done with a pen; then succeeded various grotesque figures, in attitudes to resemble letters; afterwards small Roman Capital Letters, with ornaments round them forming a square design; subsequently the block was pierced so that any letter could be introduced, and the ornamented part could be used for any initial; the next descent was for the letter founders to cast the ornament in type metal, and pierce it for general use, and these cast ornaments for letters were called Facs, as an abbreviation, I believe, for Facsimile. The last descent was to the extreme, to put a plain Roman Capital Letter, frequently extending four or five lines in depth; and this is the substitute for a beautiful coloured drawing.