Complex sentence: Based on modern analysis, it has been determined that a quill pen and iron gall ink were used for the text and figure outlines; the colored paint was applied (somewhat crudely) to the figures, possibly at a later date.
Split into simpler sentences: Based on modern analysis, it has been determined that a quill pen and iron gall ink were used for the text and figure outlines. Colored paint was applied (somewhat crudely) to the figures, possibly at a later date.