My favorite notebook is the JetPens Kanso Noto. They have 160 sheets (320 pages) of Tomoe River paper with a 5mm dot grid. Tomoe River paper is a premium fountain pen friendly paper that should solve your feathering problems.
JetPens offers free shipping in the US for order of $35 or more. I don’t know what options are available outside of the US.
The notebook is currently out of stock. I expect more to be back soon. Tomoe River paper was sold from one paper company to another. I think JetPens just cleared out their stock with paper from the original company and I anticipate they’ll bring the notebook back soon with paper from the new company (Sanzen). In the past, the notebooks sold for $19.50, which is a great price for a premium paper notebook (seriously, I think only the Nanami Seven Seas notebooks have a better price per page for premium paper) . However, to keep the price low, the notebook doesn’t have bells and whistles like an elastic closure or page marker ribbons.