Many of us have pen collections that we cherish as a whole, others have accumulations of pens that we love individually. What principles underlie your collections? How do you curate? A particular brand, country, nib style, size, filling system, era, material, color, etc.? Can your collection ever realistically be completed? Why or why not? Personally I have two collections - one of clear, monochrome demonstrators (i.e. no two-tone nibs, no colored sections or trim other than a maker's mark) and another of all matte black fp's with black or ruthenium nibs, both of which I'm sure are boring to those who love loud celluloids.