Working with master documents or subdocuments

If you ever need to work with very long documents within Word 2019, then this feature is for you! Having a particularly long document with a huge number of pages can become difficult to edit, and you have to take into consideration whether your computer can handle the processing it has to do. You can either work with the master document feature on its own or use it in combination with the subdocument feature, where parts (for example, chapters of a book) are stored as separate files and called upon when changes need to be made.

The Master Document feature is the main parent and keeps all the subdocuments connected. It will continue to allow the use of features such as page or chapter numbering, styles, references, headers and footers, and so on. Let's investigate this feature.

Always keep master documents and subdocuments within the same folder. This will ensure that you have the correct file path access to all the parts of the master documents and subdocuments and that you won't have any problems locating documents when editing, which could lead to all sorts of editing and version problems!
It is always best to name your master documents and subdocuments really carefully with some naming convention order! This way, you will not have a problem locating parts of the document that need to be in a particular order.

If you are creating a master document from scratch, open a new document as usual. Alternatively, if you want to change a normal document into a master document, open the first document, which will become the main document.

For this demonstration, we will use a few documents, that is, Master.docx, Sub1.docx, Sub2.docx:

  1. Click on File | New | Blank document.
  2. Click on View | Outline.
  3. Notice that the Outlining tab is now present on the ribbon. Click on the Show Document icon.
  4. Click on the Insert icon to start differentiating between different parts of the document:
  1. Insert your documents in order of the master, then visit Insert again separately until all the subdocuments have been added in order:
  1. You will be asked via a popup message dialog whether you want to keep conflicting styles. Say Yes to All of these to maintain consistency with the style that will be used throughout all the documents linked to the master document:
  1. Don't forget to save at this point since you have created a new document consisting of different parts.

How you continue to edit after this point is entirely up to you. Each document can be worked on separately, which will update the master document upon saving it. You can collapse and expand subdocuments and remove links from documents you no longer need to keep as part of the master. The beauty of master documents is that you have the ability to print a large document without the heaviness of one very long document.