[As our final continuation of the Feast of the Apostle of the Irish, here is one other reprint from September 2009.]
While there are various aspects of these traditions that are of great interest, the "zoomorphic" aspect has always personally struck me as particularly rich and intriguing. Zoomorphics here relate to the creation of patterns and designs using animal imagery. This might be found in the forms of letters, interlaced designs and so on.
But generally speaking, whether through zoomorphics, through more basic knotwork and complex spiral designs, through human figures and other symbols employed, not to mention the rich use of colour, it presents itself as a particularly rich tradition.
Here are just a few details, coming primarily from the Book of Kells.
(I am uncertain of the specific manuscript source of the above detail)