Why was duke Frederick ashamed to have a printing book in his library

Frederick felt ashamed to have a printing book in this library because he considered it as a inartistic source of information.

Explanation:

Duke Frederick is known to be a great manuscript dealer who constructed and maintained a magnificent library who was very famous at that times. The library is filled with various books that he had either largely purchased or collected by himself or books that he would have written on his own. In that library all the arts involved are perfectly beautiful and was written by skillful scribes. One of the interesting fact about that library is that I never had a single printed book in its collection. He would always consider printed books as trash and are designed by a mechanical work with inartistic feel and can only satisfy a group of uncultivated people.

Thus he always preferred manuscripts rather than printed books.