Directly below the Document level of the hierarchy we find the Mathwright32 Page. Each page determine the display objects that it will use. The PageManager creates and destroys these objects as one moves from one page to the next. Even though the objects on a page are destroyed when a new page is opened, the properties of those objects and changes to them persist as long as the document is open.

In an Interactive Web Book, when one moves from one web page to another, the underlying Mathwright Document is closed, and so properties do not persist between different web pages.