I wouldn't expect to find too many images of the actual liturgy itself, but there is lots of online material about fools: This site is dedicated to recreating the fool's costume, but has the references to medieval and renaissance illustrations. http://www.geocities.com/karen_larsdatter/foolwear.htm Beatrice Otto's book Fools Are Everywhere published by U. of Chicago includes a website with links. http://www.press.uchicago.edu/Misc/Chicago/640914in.html Otto's own website is called http://www.jesterlife.com/ In the ORB, Michael George writes about Laughter in the Middle Ages http://orb.rhodes.edu/non_spec/missteps/Ch10.html This site is devoted to the mythic archetype of the Trickster, some illustrations http://members.aol.com/pmichaels/glorantha/foolsparadise.html A fun subject to be working with Amelia Carr