Elsterglanz Polishing Paste
For many, part of the appeal of a "raw" pen (like the Kaweco Brass Sports, the Kaweco AL Sports and Kaweco's stainless steel pens) is the personalised patina it develops over time and with use. For everyone else, there's "Elsterglanz" polishing paste!
Apply with a soft cloth. Remove any residue with a clean dry cloth.