You can print a soft proof of a page at any time. The soft proof is displayed in a new window on your screen, as long as your computer has the Acrobat Reader installed.
To print a soft proof
Click the printer icon in the main toolbar of the Pages main tab, and then, when prompted, click No.
Note
In case you produce pages of different dimensions (some tabloid, some broadsheet, some magazine format and so on), see About media size in soft proof.