 By the end of the Middle Ages many manuscripts were produced for distribution through a network of agents, and blank spaces might be reserved for the appropriate heraldry to be added locally by the buyer.Displaying the amazing detail and richness of a text, the addition of illumination was never an afterthought.The inclusion of illumination is twofold, it added value to the work, but more importantly it provides pictures for the illiterate members of society to "make the reading seem more vivid and perhaps more credible".