Fountain Pen Cartridges
Pens, Inks & Leads · 6 specs
Direct Answer
Proprietary Fountain Pen Cartridges are brand-exclusive ink formats engineered with unique nozzle diameters and collar locking geometries that are incompatible with Standard International pens. Key proprietary systems include Pilot/Namiki (wide 5.5 mm bore), Lamy T10 (stepped collar), Sailor (flared collar), and Platinum (metal ball seal).
Source: Manufacturer Engineering Specifications (Pilot Corp, Lamy GmbH, Sailor, Platinum Pen) · Last reviewed Aug 28, 2026
Specs
| Pilot / Namiki Cartridge | Length: 59.0 mm | Wide 5.5 mm bore | Capacity: ~0.90 ml (IC-50 / IC-100 / Parallel) |
| Lamy T10 Cartridge | Length: 68.0 mm | Stepped friction collar | Capacity: ~1.15 ml (Lamy Safari, 2000, Studio) |
| Sailor Proprietary Cartridge | Length: 48.0 mm | Flared ribbed collar | Capacity: ~1.00 ml (Sailor 1911, Pro Gear) |
| Platinum Proprietary Cartridge | Length: 65.0 mm | Metal stainless steel sealing ball | Capacity: ~1.20 ml (Century #3776, Preppy) |
| Parker Quink Cartridge | Length: 76.0 mm | Stepped friction plug with reserve tank | Capacity: ~1.20 ml |
| Cross Cartridge | Length: 38.0 mm | Narrow tapered mouth (Classic Century vs Townsend / Peerless) |
Why Brands Retain Proprietary Standards
Japanese manufacturers engineered wider feed nipples (such as Pilot's 5.5 mm opening vs International's 2.4 mm) to guarantee higher surface tension ink flow across ultra-fine nibs without air bubbling. Platinum utilizes an internal heavy metal stainless steel ball bearing to agitate pigment particles and keep carbon ink suspended evenly.