rings per inch

  1. Loctite

    RPI - Rings per Inch (yes, US here, lol)

    Has anyone ever started a rings per inch chart or is it just me? I'm new to mail (started in December 2020) and I am finding that between my OCD and age it has led me to writing things down. Since I am new to mail and wanting to sell my items, but not wanting to have a large amount of projects...