20 September 2014


The world of pens, nowadays, is full of reactionary obsessions. It could not be otherwise, for fountain pens are obsolete tools. Consequently, once this point is accepted and understood all cravings are allowed—-ancient materials, old filling systems, outdated manufacturing techniques…

One of the debates involves the material out of which the feed is manufactured. Old pens, before 1950s, used ebonite (vulcanized hard rubber) and around that time different plastics made their way as the material of choice for feeds as it is today. Ebonite, though, is still used today mostly on high-end pens. This is often used as a selling argument, although Montblanc’s flagship pen, the 149, uses plastic feeds. Many a stylophile are happy to buy that argument and swear by ebonite as the ultimate material to provide a good (and generous) flow of ink to the nib.

But, is the feed material that important for the final performance of the pen? Or, in other words, what are the differences between these two materials, plastic and ebonite?

The main difference lies in the way the ink interacts with those two surfaces. Ebonite is hygroscopic and favors capillarity and circulation of the ink along the ink channels.

On the other side, on plastic ink forms drops and its flow becomes more difficult. There are some ways to correct this issue: by making the surface rougher (“unpolishing” it) the specific surface of the channels increases and the ink smears along them. Another strategy was to add some hygroscopic layer to the feed.

But the final conclusion might be that due to that problem –the ink not wetting the plastic feed— ebonite should be the obvious option. However, ebonite carries its own problems to the production line—it is more expensive than plastic and needs to be cut. Ebonite oxidizes in the wrong environment, and its purity (or the presence of impurities in it) plays an important role in the final quality of the manufactured good. The final result is that it is not unusual to see deformed, bent or cracked pieces of ebonite, in feed or in other pen parts.

Ebonite feed from a Platinum pen from around 1935.

Section, nib and feed of a Super T Gester from ca 1960. This feed, made of ebonite, was bended and could not drive the ink to the nib efficiently.

Plastic, on the contrary, can be molded into the desired shape, and is very stable chemically. So, plastic is cheap, fast and reliable.

Two plastic feeds by Platinum from the late 1950s. The one on the left was misstreated, whereas the one of the right has never been used. Both preserve the original shape.

Well designed feeds, on their side, do work well and are able to provide fairly big flows of ink. Case in point—the Nagahara’s two- and three-fold specialty nibs are attached to plastic (ABS) feeds. There are no complaints in the pen community about their reliability, and they show that a proper design does the job despite the limitations of the material.

Plastic feed of a cross-music nib by nibmeister Nagahara. But in fact, all feeds are the same for a given nib size in the Sailor catalog.

Some argue that plastic feeds have not passed the test of time and that we cannot really asses whether they might degrade with time. And they go further into saying that we can also find perfectly preserved ebonite feed after many years of use or storage. But we also know –and that is the point here— that ebonite feeds are vulnerable.

After all these considerations, personal preferences and romantic ideas come. And they are welcome, for writing with these tools is in itself romantic and anachronic.

Pilot Custom 74, music nibGary’s Red-Black

Bruno Taut
Nakano, August 15th, 2014
etiquetas: soluciones técnicas


Anonymous said...

Good questions. I want to say ebonite, but the plastic feed on my music nibbed 3776 does a great job.

Has anyone used any of the other plastics to make feeds?

Are there more modern materials, with new properties that could be tried out? Just a random thought, but would a modern, ultra tough, glass feed do anything?

Flounder said...

I have been following a peculiar Onoto auction, item number 261596670434.

The under-over feed is gold!

Anonymous said...

Yes you mention Ebonite can warp over time. However you fail to mention that Ebonite can be heated and molded to shape again and again. A case in point is how nibs and feeds are "heat set" to each other to improve flow - something that is very important with flexible nibs so the feed can supply enough ink. Heat setting a plastic feed is next to impossible - which is a major disadvantage of plastic. Thank you for the post, David

Anonymous said...

Quick point:

Does the same apply to italics, and is that why old italic pens, with their correctly fitted ebonite feeds, work wetter and are more accommodating to writing?

Post a Comment

Your comments are welcome and appreciated.