Good quality for fountain pen use
I was really expecting a lot of bleed-through at this price point, but the paper surprised me. I've used Iroshizuku, Noodler's and Diamine inks on this notebook (in a Pilot Metro with a fine nib) and only get bleed-through where I scribble. Even then, it's just a tiny spot of bleed-through.
The paper has tooth, so if you're looking for something like Tomoe River paper or Clairefontaine, this notebook might not work for you. If you don't mind a little feedback, and are looking for an inexpensive option that matches your Carpe Diem planner, give this one a try.