Pen cases I found are incredibly expensive so I found this incredible alternative and thought I'd share it with you. My collection isn't big so one side is fountain pens, stub pens,
Premium Genuine Leather Pen Case - Perfect for Single Pens! | Walmart Canada
Custom leather pen cases and sleeves
Wancher Genuine Leather Fountain Pen Case Cowhide Single Pen Holder Pouch Sleeve Pen Bag Office Accessories - AliExpress
Wonder Pens: Life Japanese Stationery Leather Pen Case - Brown
Leather Single Fountain Pen Case/Pen Pouch - Brown - Galen Leather