What is “ink flow”? Simply put, ink flow describes how much ink is being put onto the paper by the nib and feed. Generally a pen can be placed anywhere on a spectrum from dry to wet, and there are multiple factors that will determine such a performance.
1) The Ink
Inks, just like pens, can be described as wet or dry. What exactly makes an ink wet or dry is dependant on the chemical components of an ink. Here’s a quick overview:
Generally speaking, there are 3 different types of inks:
a) Dye-based inks, are inks where dye is dissolved in the water. Dye-based inks make up about 90% of all fountain pen inks and are generally the safest inks to use in fountain pens. Brands include Waterman, Sailor, Pilot, etc.
b) Pigment-based inks are the oldest form of inks, where solid pigments a suspended in a solvent (usually water). Examples for pigment-based inks are Sailor Sei-Boku and Platinum Carbon Black.
c) Lastly, we have iron gall inks made from iron salts and tannic acids from vegetable sources. Examples for iron gall inks are for instance Pelikan 4001 Blue Black or Rohrer & Klingner Scabiosa.
The main components to be found in fountain pen inks are the following: a solvent (usually water, in order for it to actually be fountain pen friendly), a spreading agent also referred to as the lubricant that will allow the ink to glide across the paper, wetting agents that allow the solvent and pigments to attach themselves onto the paper, and, lastly, mold inhibiting preservatives.
2) The Feed
The feed, as shown in the image above, is the part of the pen that transports the ink from the ink reservoir in the back of the pen underneath the nib, which will then, through capillary action, further carry it onto the page. Feeds are usually made of hard rubber, plastic or ebonite.
The most important effect that a feed has on the ink flow are the characteristics of the ink channel on top of the feed. In particular, the width, depth and porousnes of the nib material will have the greatest influence on how a pen will perform in regard to its ink flow.
Not unimportant is also the positioning of the feed in relation to the nib. Should the nib and feed not touch, ink will have a hard time travelling from the feed to the very tip of the pen.
3) The Nib
The last factor that’ll influence a nib’s performance in regards to the ink flow is the nib itself. More specifically, how the tines of the nib are positioned to each other.
The images below demonstrate what the ideal distance and positioning to each other should be. Image one portayes the ideal nib where the tines taper together part are never pressed too tightly against eachother, allowing for a generous, yet controlled ink flow. The second nib in this image is sprung. Ink would hardly make it onto the paper with this nib, as the ink’s surface tension would likely break, which would keep the capillary action from ever coming into effect. The third nib shown in the picture has tines that are very tightly pressed against eachother, which wouldn’t allow for generous ink flow, but rather for a dryer writing experience.