I was able to visit the Getty Center in Los Angeles last summer. I was planning to head straight for the post-impressionist art I love, when I happened to go into a room full of illuminated manuscripts. Wow! I was completely captivated. They are truly amazing.
These books were all made on parchment (calf, sheep or goat skin), by hand. Before the rise of universities in the 13th century, manuscript production was done by monks in monasteries. When demand for books grew, manuscripts were then produced in urban centers. Commercialization led to the rise of professional parchment makers, scribes and artists. Once the parchment has been prepared, the body of the text was written. Space was left for fancy initials and illustrations. If used, gold was then added and finally pigments were added last as they were the most expensive. I had trouble picking just a handful of images to put on here, the Getty has literally hundreds of incredible pages in their archive.
Images taken from the Getty's Open Content Program.