# item.guide
Side-by-Side Comparison Pens, Inks & Leads

Fountain Pen Nib Widths vs. Fountain Pen Cartridges

Comparing 2 standards across 14 specifications. 14 key differences identified.

Comparing:
Fountain Pen Nib Widths
Fountain Pen Cartridges

Fountain Pen Nib Widths are standardized tip grinding grades that determine ink line width, categorized from Extra Fine (EF) to Double Broad (BB) and Calligraphic Stubs (1.1 mm to 1.5 mm). Crucially, Japanese nibs (Pilot, Sailor, Platinum) write approximately one full step finer than Western nibs (Pelikan, Lamy, Kaweco) due to the dense stroke requirements of East Asian kanji characters.

View full Fountain Pen Nib Widths spec sheet →

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).

View full Fountain Pen Cartridges spec sheet →

Specification Comparison Table

14 Parameters
Parameter / Spec
Extra Fine (EF)–Japanese
Approx. 0.20 to 0.28 mm line width (hairline precision)
Extra Fine (EF)–Western
Approx. 0.35 to 0.40 mm line width (similar to Japanese Fine)
Fine (F)–Japanese
Approx. 0.30 to 0.38 mm line width (standard everyday Japanese notebook writing)
Fine (F)–Western
Approx. 0.50 to 0.60 mm line width (similar to Japanese Medium)
Medium (M)–Japanese
Approx. 0.50 to 0.58 mm line width
Medium (M)–Western
Approx. 0.70 to 0.80 mm line width (plentiful wet ink flow)
Broad (B) & Stub (1.1 / 1.5 mm)
Broad: 0.9–1.0 mm | Stub: Flat rectangular tip with thick downstrokes and hairline cross-strokes
Tipping Material
Sintered osmium/iridium/ruthenium platinum-group alloy sphere welded to gold or steel tines
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)