This is a grid notebook ruled into 5mm squares for the Passport sized TRAVELER'S Notebook. This makes it easy to write and draw figures on. It’s worth mentioning that it doesn’t look bad when you write and draw beyond the grid. Our original paper (MD paper) is used for this refill. MD Paper pursues the best feeling of writing, and ensures ink doesn't stain or bleeds through to the other side of the paper. It goes well with fountain pens as well.