I saw a version of this bag in one of Tokyo Pen Shop's YouTube videos two years ago, and immediately fell in love with it. It's called the Estia Leather Accessory Bag by Milloo. Milloo is a company that makes bags by hand out of cotton, canvas, and leather in Athens, Greece. They mainly sell their bags through their Etsy store. At the time I purchased mine, the only way to get one was to order one through their Etsy store, but now Tokyo Pen Shop sells them as well.
My bag is the brown leather version-I love the color and feel of the bag. They also make cotton, canvas and different colored leather versions. According to the Milloo Etsy shop, "Aprox. dimensions: The bottom is measuring 9.5" x 4" (24cm x 10cm) and the height of this pouch is 5" (14cm)." It's long enough to fit a new blackwing pencil without breaking the tip.
I'm not crazy about the tassel on the zipper, but you could always replace it with a keychain instead.
The bottom of the bag is nice and flat, which allows the bag to sit upright. I hate bags that are constantly tipping over, but this one does a great job of sitting upright.
One end has a nice carrying handle.
The other end is stamped with the Milloo name. I like that the branding is subtle, and no so in your face as some other brands are.
The bag has a nice cotton lining, mine is brown and blue stripes. There is a small inner zip pocket on one side.
This bag holds a lot. The picture above shows what I'm currently storing in this bag: 19 pencils, 11 highlighters, 7 Lamy Safari/Al-Stars, and 21 pens, and there is still room for more. I wouldn't store expensive fountain pens in it-since they might scratch each other, but I have no problem throwing Lamy Safaris in it.
I've had this bag for over two years and it's still one that I use daily. Yes, I know it's not technically a pencil case, but it works great for pens and pencils. It holds a ton, and still looks new after two years of constant use. I have a few different versions of this bag, and I have never been disappointed by anything I have purchased from Milloo. They do a great job.
Disclaimer: I purchased this product myself, and all photos and opinions are my own. This page does not contain affiliate links.