The elastic weaving of figure and plant motifs so typical of romanesque illumination gets more and more untangled towards the gothic period. Human figures don't have to bend and stretch to fill or fit the initial letter anymore.
These more naturalistic poses and proportions in gothic initials result in increased open space within the shape of the enclosing letter. These spaces get filled with solid color or patterns.
I just might revisit these pattern explorations printed a few years ago.