I bought and tested 14 different types and brands of paper from National Bookstore to see which papers are good for brush lettering, watercolor wash technique, watercolor blending, and blending using a colorless blender pen.
As mentioned in the video, here's a link to buy my notebooks:
Here's a summary of the papers I tested showing which papers are good for which techniques. The ones with a red thumbs down means that I recommend that you won't use that paper for that technique (e.g. hand-lettering, watercolor washing). The ones with green thumbs up are the ones I highly recommend.