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Mentmore Manufacturing, inventor of the cartridge pen, the retractable ballpoint pen, and the felt tip,
of Eureka Works, 16 Mentmore Terrace, Hackney, London, E8. (1922)
of Tudor Grove, Hackney, London, E9. Telephone: Clissold 5400. Cables: "Fountapen, London". (1929)
of Station Road, Wood Green, London, N22. Telephone: Bowes Park 2997. Plastics Division. (1947)
1919 Platignum Pen Co started life as the Mentmore Manufacturing Company, named after its first premises in Mentmore Terrace, London. The company's first product was a self-filling fountain pen with a gold plated nib which sold for 6d (2½p).
1922 British Industries Fair Advert as Makers of kinds of Fountain Pens and Stationers' Sundries in Ebonite, Erinoid, Galalith, etc. Pens Stamped and Boxed with Customers' Own Marks. Specialities: Penholders, Paper Knives, Self-Pointing Pencils. (Stand No. K.166) 
1925 The first replacement nib unit was developed - a revolution in pen design. The Platignum name was also introduced, and the slogan 'As good as gold' to reflect the use of stainless steel for the first time. Mentmore were anxious to register the name Platinum, but were unable to do so because it could have contravened the laws of product description - as they existed at that time. To overcome the problem, a company was registered in the name of the "Platignum Pen Company", and products carrying the brand name Platignum were introduced. Platignum were the first company to use injection moulding in the production of their pens.
1929 British Industries Fair Adverts for 'Spot' Pens and Propelling Pencils; 'Platignum' Lever Self Filler fountain Pens; 'Platignum' Writing Sets. Manufacturers of Fountain Pens of all kinds, Gold Nibs with iridium points, Permopoint Pencils, Advertising Novelties, Penholders, etc. Goods imprinted and boxed to Customers' requirements. (Stationery Section - Stand Nos. R.32 and R.126) 
1935 Public company incorporated
1939-45 The outbreak of the Second World War meant that Platignum was only allowed to produce 25% of its pre-war pen output, with the major production concentrated on munitions, aircraft parts and cap badges. The War Office entrusted the company with the making of special 'spy' pens which could contain maps and compasses. A deadlier model was also produced for use by secret agents - it contained a poisoned dart which could kill at 20 ft!
1947 British Industries Fair Advert as Manufacturers of Mass produced Articles in Plastics for all Trades. Specialists for Twenty Years in Injection Moulding; the Most Economical Method of Mass Producing Articles in Plastic for all Trades. (Plastics Section - Olympia, 1st Floor, Stand No. H.2161) 
1950 The company marketed their own version of the ballpoint pen for 5/- (25p), and soon after invented the retractable ballpen. Platignum, also around this time, invented ink cartridges.
1951 Advert on this page. 
1957 A move to Stevenage meant more space and allowed the company to diversify into plastic stationery accessories and fibre tipped pens.
1984 Platignum relocated to its present site in Royston.
1987 Acquired Ouvah Highfields
1992 Disposed of Ouvah Highfields, a serviced-office-centre subsidiary
1996 Acquired Abbey self storage; name changed to Mentmore Abbey