Fountain Pen Nib | Pro-Flex

A Professional Nib for Serious Flex Writing

The Pro-Flex Nib is a titanium-coated Zebra G designed for advanced calligraphers who want exceptional flexibility and control. With a super-fine point that flexes from delicate hairlines to bold 2 mm strokes, it delivers expressive results — but requires a practiced, light touch. For this reason, it’s recommended only for experienced calligraphers.

A key innovation is its integrated leaf-spring feed system, which keeps the feed in constant contact with the nib as it flexes. Where most flex pens fail due to ink starvation, this design maintains consistent flow and even includes a small internal “sump” to store excess ink, releasing it as the nib demands.

If you’re a fountain-pen user exploring flex for the first time, start with the Semi-Flex or Titanium Flex nibs before moving up to the Pro-Flex.

The nib housing is a Bock 250 (size 6), compatible with all Tom’s Studio fountain pens and many others using the same standard.

Unlike standard stainless-steel fountain pen nibs, calligraphy nibs use softer alloys for enhanced flex — but they corrode more easily. The titanium coating on the Pro-Flex dramatically extends its life, lasting up to six times longer. When it eventually wears out, simply remove it with pliers and replace it.

Because this is a high-flow (“juicy”) nib, occasional leaking can occur, especially during travel. To prevent this, remove the ink cartridge or converter before storing or transporting your pen.

Eye-dropper pens may also experience inconsistent flow or “ink burping,” which can affect high-demand nibs like the Pro-Flex. If this happens, switch back to a cartridge or converter for steadier performance.