I opened the drawing explorer (View > Drawing Explorer), expanded "Background
Pages," and right-clicked on my background page, but the context menu does
not display a protect submenu. The context menu displays only "Page
Setup...", "Ruler & Grid...", "Delete Page" and "Show ShapeSheet." In the
ShapeSheet, I see a Page Property named "UIVisibility," which can take on one
of two values ("visUIVNormal" or "visUIVHidden"). Setting UIVisibility to
visUIHidden makes the background page invisible, in that the tab for the page
disappears from the drawing window and the background page's entry disappears
from the drawing explorer. However, now, when I insert a new page (Insert >
New Page), the background page is no longer available.
Is there a way to make the background page hidden, in that it doesn't have a
tab on the drawing page, yet it is available as a background page for new
page insertions?
BTW, how can I set UIVisibility back to visUIVNormal? (This is an academic
question, because I did not save the changes to my drawing.)