Illuminated manuscripts are one example of pre-printing. These manuscripts were handwritten, often religious in nature, and embellished and decorated with elaborate designs and miniature paintings. Originally the term "illuminated" denoted the text was embellished with either gold or silver, however today the meaning has generally come to refer to illustrations and decorations in preprint-era manuscripts. With the advent of the printing press, illumination was replaced by printed illustrations. Archives and Special Collections houses a variety of original illuminated manuscripts, as well as facsimiles of rarer texts such as,The Book of Kells.
Source: Britannica Concise Encyclopedia. Chicago: Encyclopaedia Britannica, 2009. s.v. "illuminated manuscript."
Leaf from a 15th Century Book of Hours