The paper inside the notebook is a pleasing eggshell color and performs really well with basically any kind of writing instrument. The 5mm grid pattern is an old standard, and it's done well in this notebook. The grid pattern is full-bleed across the pages, and I appreciate that the pages cuts are done in a way so that there aren't any awkward half or 3/4 grids around the boundaries of the page. Again, there's an obvious attention to detail here that pleases the part of my brain that craves order and structure. Another part of my brain that appreciates mistakes and messes is also happy because this paper can take anything you throw at it. I haven't seen any bleeding or feathering, and there's hardly any show through on the back of the page. You can easily use both the front and back of each page. Speaking of pages, this notebook packs 96 of them while still remaining fairly slender.
Writing with this notebook is fantastic. The pages lay flat on their own, so you're free to relax and write, doodle, or whatever. Pens and pencils feel great when writing on this paper, and the ink dries fairly quickly (varies a bit based on how wet/wide the nib is). Overall, it's a joy to write on, and it rivals some of my favorite notebooks to date.
On top of all that good news, the Yu-sari notebooks (the A5 size) retail for $12.50. That's a stupidly good price, and you should pick one up if/when you have the chance. The larger B5 books retail for $17, which is also a good deal considering the large size.
(Vanness Pens provided this product at a discount to The Pen Addict for review purposes.)