Something kind of neat that a lot of fountain pen users tend to do with written correspondence is to write the name of the pen (with nib type), the type of ink, and paper used at the bottom of the letter. There's no particular order, you're really just sharing the information with your recipient so they have 'samples' of the products you prefer to use. Since most of us pen fanatics tend to be spread far and wide, this kind of 'in your hands' example is a great way to share with your friends the products that inspire you while you write. Try it next time you write a letter!
Link to YouTube for iPhones and full-screen viewing.