Luxury manuscripts were given treasure bindings or rich covers with jewels set in gold and carved ivory panels, and, as in Insular art, were prestige objects kept in the church or treasury, and a different class of object from the working manuscripts kept in the library, where some initials might be decorated, and pen drawings added in a few places. A few of the grandest imperial manuscripts were written on purple parchment. The Bern Physiologus is a relatively rare example of a secular manuscript heavily illustrated with fully painted miniatures, lying in between these two classes, and perhaps produced for the private library of an important individual, as was the Vatican Terence.