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

Fountain Pen Nib Widths vs. Standard International Cartridge

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

Comparing:
Fountain Pen Nib Widths
Standard International Cartridge

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 →

The Standard International Cartridge (also known as the European or Universal cartridge) is the dominant standardized fountain pen ink format, featuring a 2.4 mm nozzle opening sealed with a plastic sphere. Available in Short (38 mm / 0.85 ml) and Long (72 mm / 1.4 ml) sizes, it is used by dozens of European and American fountain pen manufacturers.

View full Standard International Cartridge 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
Short Cartridge Dimensions
38.0 mm length × 7.0 mm diameter (approx. 0.80 to 0.85 ml ink capacity)
Long Cartridge Dimensions
72.0 mm length × 7.0 mm diameter (approx. 1.40 to 1.50 ml ink capacity)
Bore / Nozzle Diameter
2.4 ± 0.05 mm (friction-fits over the pen feed nipple)
Internal Seal
Floating polystyrene bead / puncture disc pushed into cartridge body upon insertion
Two-in-Barrel Tandem Storage
Most full-size pens store one active short cartridge plus one inverted spare short cartridge in the barrel
Brand Compatibility
Kaweco, Pelikan, Montblanc, Faber-Castell, Visconti, Diplomat, Caran d'Ache, Jinhao, Waterman (long)