As you can probably guess, I am very particular about my notebook and the kind of paper I use. I carry my notebook with me everywhere I go so I like to have it protected in a durable way, and last year for my birthday, my wonderful father-in-law bought the Gfeller cover I had been drooling over. The cover with the notebook I use inside it look like this:
You can buy the covers both with and without the pen loop that you see on the right side of the notebook. I like the pen loop because it helps me always keep track of my pen as well as providing some protection for the pen from dings and scratches. It also keeps the notebook closed because the center loop is attached to the back cover while the outer loops are attached to the front.
The leather on the cover is top-notch and comes completely untreated. This means that oils from your hands or (in my case) a little accidental rain water will add to the patina. When it comes, the leather is about the color of silly putty but this changes as you expose the leather to the sun. The summer I got my cover, I left it on the dashboard of my car for a few hours every after noon when I went into the library. This quickly darkened it to the look I wanted. If you google ‘Gfeller’ you can see many other ways that people have dyed or added shoe polish to their cover.
The notebook itself is a Midori MD stitched notebook. If you buy one, I highly recommend buying them from that link at Goulet Pens (no affiliation). I have had very good experience with their customer support in the past. This Japanese paper is my favorite paper for writing with fountain pens: extremely smooth with zero bleed. It is thinner than Clairefontaine/Rhodia paper but similarly resilient. It is also slightly off-white shading toward yellow while Clairfontaine/Rhodia paper is (to my taste) blindingly white.