The Book of Kells is a masterpiece of western calligraphy. It is written in a beautiful insular majuscule script, and is the work of at least three different scribes. The lettering is written in iron gall ink, and the colours used for the illumination use a wide range of substances, many of which were imported into Ireland.
The book has been scanned in its entirety and has been made available online by Trinity College Dublin. HERE.