Once you've loaded up your jounal's 2 removable inserts, simply pull them out and replace with a couple of spares, available right here. (seriously, you're going to fill this thing up, so don't skimp on the spares)
Each journal includes 2 pre-loaded inserts of 30 sheets (60 pages) each.
Price of replacements includes 2 new inserts.
Size
5" x 8.3" (A5) inserts
3.5" x 5.5" inserts