Just like publication pages, a master page can be a single page or a spread with two or more pages. A master can be applied to all or some of another spread's pages.
When creating a new document, a default master can be created and applied to all publication pages created at this time. After this, you can apply any new master at any time using the Pages panel.
Masters can be applied to other masters in more complex documents.
For example, a 'parent' master containing just page numbering could be applied to multiple 'child' masters coloured separately for each of your publication's sections. This means that to change your page numbering style, you only need to do so on the parent master.
Also, as you create new publication pages, applying a child master to them adds the section colouring and automatically inherits page numbering from its parent.
An applied master is actually a layer, which shows on the Layers panel as a vertical solid turquoise marker prefixing the thumbnail on the layer entry.
The layer can be expanded to expose the elements inherited from the master, which display vertical solid turquoise markers on their entries.
When an element of a master page is edited on a page where it's applied, that page's layer entries for the element and its master page display dotted turquoise markers.
By dragging a master's layer to the top of the layer stack, you can present the master's items in front of all other items on the page.
By selecting the master page's layer entry, the inherited content can be collectively transformed. Individual objects can only be transformed by detaching the master page. The content of text objects and picture frames can be edited, though.
To prevent inadvertent transformation or editing of inherited content (other than text/picture frame content), select and then lock the master layer on the Layers panel.
You can manage how a master is applied in the Master Placement section of its layer options, where you can specify:
The following scaling behaviours are available:
On the Pages panel:
On the Pages panel, do one of the following:
On the Pages panel:
On the Pages panel:
On the Layers panel:
Do one of the following: