Montblanc pen. Writers Edition Sir Arthur Conan Doyle. Limited Editon Rollerball. Made from blue-gray precious resin, the edition evokes the sinister, foggy atmosphere of London, where Sherlock Holmes usually solves his cases. The cap and barrel of this edition are decorated with a plaid pattern in reference to Holmes' coat, as well as parts of a historic London city map. The initials JB are found beneath the PVD-coated, magnifying glass-shaped clip.