Fun Fact: Contemporary plastic feeds are made from the same plastic used in the manufacture of Lego blocks – so I’ve been told – hmmm. I did not verify this with Lego.
Plastic feeds are now designed with specific surface properties to promote ink flow by capillary action, this was not always the case and for near-perfect air compensation. These plastic feeds are injection molded for economic and precision mass production, benefiting the bottom line, quality control, and user experience. Through injection molding, manufactures are able to attain such a tight tolerance as to eliminate heat fitting. In this fashion, everybody has the same experience and you can be assured that the next pen purchase will be as enjoyable if not better than the previous purchase.
Visconti switched to plastic feeds for two reasons, quality and performance. I’m hearing this 3rd hand but they claim the average quality of a plastic feed is much higher than a well-made ebonite feed. Through plastics they were able to better manage air compensation, permitting higher air pressure gap management. Don’t forget that 70 years ago commercial air flights were rare; therefore, air compensation was limited to weather changes and skyscrapers.
Plastic feeds, from what I have read, need to be treated with an etchant or something similar to achieve a similar effect. Remember it is not possible to tune a plastic feed. An engineer with Lamy, (again hearing this 3rd hand) said of plastic feeds, “it took a lot of different chemical treatments to make the plastic feeds as rough as the sawn (a past participle of saw) ebonite ones.” While others claim chemicals were never used on plastic feeds to make them wettable.
Plastic feeds need more time to properly function when the nib is applied to paper. The smooth surface of the plastic repels water and requires a rough finish to allow the ink to flow properly via capillary action. Thus if you manually adjust a plastic feed by cutting an ink channel, there is a chance the surface will repel the ink and the feed will no longer work.
Ebonite pen feeds are handmade on a lathe and mill like vintage pens, the human element adds to the personality of the pen. Hard rubber (ebonite) was one of the first, if not the first plastic. Establishing a tradition! Along came ABS Plastic with the advantage that feeds can be mass produced using injection molding, a process not only much cheaper but more precise, delivering more consistent quality of performance to the pen owner.
BECAUSE, like so often with tradition, things are done the way they have always been done – BECAUSE. Ebonite feeds should still be machined from hard rubber but not BECAUSE, but for the novelty and to honor the tradition.
To close, lets answer the question of which material makes a better fountain pen feed. Applying Sherlock Holmes’s deductive reasoning, ebonite is hard rubber which is considered plastic. Whereas, acrylonitrile butadiene styrene is plastic and considered plastic thus feeds made with either material is made with plastic, argument solved!
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