As you may know the Hobonichi uses fountain pen friendly Tomoeo River paper. I used fountain pen exclusively. The paper is thin and while bleed through isn’t a problem there’s some show-through. In general show-through never bothers me and I regularly use both sides of any paper. With my thin nibs the show-through is there but minimal with the Hobionichi. What does bother me is the time it takes for ink to dry on this paper. I cut a piece of blotter paper to fit the Techo and place between the pages. In addition to making my current page easy to fine it keeps the ink from transferring to the facing page when I close the book. Sure, I could wait for the ink to dry but that would require patience. Plus, it provides a bit of a cushion to write on if I’m using a hard thin nib that might leave an imprint on the page below the one I’m writing on.
Yeah, the dry time is painful, but that is also the only problem I have with the Hobonichi.