With the Redactor add-on you can insert a PDF document before and / or after your Redactor document.
This allows you to insert, for example:
To insert a PDF, click Layout in the document builder:
In the first block, you can load a PDF (it will be stored in Files> My Documents).
Note that you can also use a page background if it has been defined in the Redactor add-on settings (in the Store).