...illuminated manuscript

Further reading on this topic discover that the material(animal skin) affect the look and the cost of the book:
1) the size of the book determine by the size of the skin and the budget available.
2) expensive due to shortage of animal skin- the monks were vegetarian.
3) determine the shape of the book- landscape/portrait.
4) had to have a heavy cover to keep it flat.
5) bulky - the thickness of the skin.
6) some pages had scared.

As I read on further, looking into the decorative elements on the manuscript, they serve as:
1) as a full stop
2) as start of a paragraph
3) as quote/references
4) as filler to fill up the empty space in the page
5) as symbolic rather than direct relationship to the text.

The colour used depict the social status of the owner - the more gold and blue used, the richer and more powerful they are.
(the blue pigment - made out of ultra marine, a type of gemstone grind into powder form, very expensive at that point in time)