TWSBI Vac700R Iris Fountain Pen - F Nib

The Vac700R is the most serious pen TWSBI makes, and the filling system is the first thing that tells you so. Instead of a twist piston, it uses a vacuum mechanism: pull the plunger back, dip the nib, push down once, and the barrel draws up to 2.37ml of ink in a single stroke.

A built-in shut-off valve seals the reservoir from the feed when the end cap is closed, making it one of the only fountain pens you can actually fly with without emptying it first.

The clear resin barrel tapers toward a faceted end cap with the metal vacuum rod visible through the body, giving it a mechanical, industrial look that sets it apart from the rest of the lineup. The nib is a #6 stainless steel, the largest TWSBI makes , and it writes wetter and smoother than anything below it, with more ink flow and more presence on the page.

The GO starts the habit, the ECO sustains it, the 580 deepens it, and the Vac700R is what you reach for when the habit becomes something you take seriously.

Please note: Ink is NOT included

A quick no-brainer guide in choosing nib sizes in an overly complicated fountain pen world:

If you write small, go with an EF
For the normal writer, F is the most popular
If you tend to lean on a bigger font, M will be perfect
B is for statements!! Sign a check in B, write a header in B, do some coloring/shading in B
Stub nibs are italic in writing style (have a special card or invitation to write?)