Design Features: Visible Ink Supplies

(This page revised April 3, 2014)

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How much ink do I have left? Once Lewis Waterman had pretty much solved the basic problem of providing a reliable ink flow and had, for most purposes, reduced blotting to a relatively minor concern, the worst thing that could happen to a 19th-century user of fountain pens was to have a pen run dry when far from a supply of ink. But how do you tell when you’re in danger? This article describes and illustrates the systems pen makers devised to help the user be sure of having a full tank.

Baby Steps

Before the turn of the 20th century, pens were made of hard rubber, and little could be done to help the user to answer the question of how long until the gauge would hit Empty. One attempt to work around the limitations of opaque material was patented in 1899 by Albert A. Hofmann (U.S. Patent Nº 623,474). Hofmann’s approach was to machine lengthwise slots in the pen’s barrel and insert into the slots strips of a transparent material such as glass or mica, with a packing material to seal the seams. The section secured the transparent strips in place, rendering the barrel ink tight. Hofmann did not supply a model for his patent, and no manufacturer is known to have marketed pens produced to Hofmann’s design.

Another attempt surfaced in 1905 with the first mention of celluloid for providing a transparent window into a pen. James G. Marshall’s approach (U.S. Patent Nº 793,598) was to create “portholes” by drilling small conical holes through the wall of the barrel and fitting a thin band of celluloid inside the barrel, where it would be cemented into position, to provide the “window glass.” There was no model for Marshall’s design, either, and nobody is known to have produced it.

In 1907, things changed with Leo Baekland’s discovery of Bakelite, a thermosetting resin that could be used to produce transparent pen barrels. Suddenly any pen that used its barrel as a reservoir, including some self-fillers as well as the ubiquitous “regular” pens (eyedropper fillers), could have a visible ink supply. Among well-known pens to appear with Bakelite barrels were Parker and Waterman eyedroppers; and, later, Dunn-Pen self-fillers. Most Bakelite barrels were made in a ruby red color, but there were also amber barrels. Shown here is a Dunn-Pen pen with a Bakelite barrel:

Fountain pen Magnifying glass

The problem with Bakelite is that it’s rather brittle. It cracks and shatters easily unless it is reinforced by a fibrous filler such as asbestos or cotton. Adding the filler makes the material opaque, losing the desired benefit of a visible ink supply. Pen makers wanting a practical transparent material had to wait until celluloid made its appearance in the 1920s.

Let’s Walk!

Celluloid, introduced to the market by DuPont, offers a tremendous variety of design options. The most obvious choice is to make a barrel of completely clear celluloid, or perhaps of celluloid that has been tinted to a uniform transparent green or brown color. Just such a pen appeared in 1929, with Pelikan’s introduction of the world’s first successful piston-filling pen. At first, the Pelikan pen did not even have a model number, but within a year the company began calling it the 100, to distinguish it from future models. The Pelikan 100 shown here has a barrel made entirely of green-tinted transparent celluloid; the marbled green area is a celluloid Binde (sleeve) fitted over the distal portion for appearance.

Fountain pen Magnifying glass

The remainder of the Golden Age produced more Pelikans, along with piston fillers of many other brands. Shown here are a Pelikan 101N and a Soennecken 118, both featuring transparent ink windows:

Fountain pen Magnifying glass
Fountain pen Magnifying glass

But there are other ways to let the user see the ink level than to stick plain old clear celluloid in the barrel. By using a striated or marbled celluloid, the maker can incorporate transparent parts into the design, creating a more unified appearance. Here are a Matador 811 (German), an Aska (Swiss), and two Conklin Nozacs (American). These two Conklins’ transparent areas have darkened so that you cannot see through them in the photos here:

Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass

Getting Better

In 1932, Parker test-marketed the Golden Arrow, which a year later became what is perhaps the best known of the visible-ink-supply pens, the Vacumatic. With its dramatically jewel-like lateral striations the Vacumatic offered a full-length picture of its ink supply by alternating clear bands with colored. Possibly riffing on the 1929 demonstration of an experimental TV, Parker called its visible-ink feature the Television Ink Supply. Here are two Vacumatics, one from 1934 and one from 1946:

Fountain pen Magnifying glass
Fountain pen Magnifying glass

Two years after the Golden Arrow appeared, Sheaffer began producing plunger-filling pens. The company sold these models, in marbled, snakeskin and other patterns, under its Vacuum-Fil and WASP sub-brands (below, first pen) until it had confidence enough in the filler to introduce Sheaffer-branded pens with it. Wahl-Eversharp quickly followed suit with a plunger-filling version of its Doric, calling its filler the One-Shot vacuum filler (below, second pen). Although Wahl-Eversharp discontinued the One-Shot filler with the 1938 retirement of the Doric, Sheaffer continued to produce Vacuum-Fil models until 1949. The third pen shown here is a "TRIUMPH" Autograph from the World War II years, and the fourth is a Tuckaway Sentinel from immediately after the War. The Tuckaway features a revised design, and its transparent area extends only about 1/3 of the barrel’s effective length.

Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass

Adapt, Adapt!

How do you apply a transparent barrel to a sac-filling pen? There are two ways, and both appeared during the Golden Age. The easier method is to make the pen a bulb filler, which uses a shortened sac as a pump to fill the barrel in much the same manner as the Parker Vacumatic. This is how Dunn had done it back in the days of Bakelite, and this is how Wahl-Eversharp did it with the Bantam, introduced in about 1932. The pen has a blind cap about half the total barrel length, and removing the blind cap reveals the bulb for the user to squeeze with his or her fingers. The Bantam appeared in many colors and variations, including even a small desk pen with base. Many have partially transparent barrels: the first pen here shows the same ribbonlike design as on the Doric above, and the second’s barrel is opaque marbled celluloid with a very narrow clear band right above the threads.

Fountain pen Magnifying glass
Fountain pen Magnifying glass

Soennecken and Waterman each took the bulb filler one step farther. Soennecken built a button-filling system into the blind cap, complete with a screw-threaded collar that locks the button against inadvertent pressing (instead of a second blind cap!) while Waterman designed a double-acting lever to operate the pressure bar (U.S. Patent Nº 2,087,672, by Gabriel Larsen and Henry N. Briechle). Both of these designs require multiple strokes to fill, just as with a bulb that you squeeze manually. Shown here are a Rheingold 613 by Soennecken and a Copper-Ray Ink-Vue by Waterman.

Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass

The Light Goes On, All Over the World

But adding a visible ink supply to a lever filler, whose sac extends the full length of the barrel, took a sudden insight, in the form of a partially transparent gripping section patented in 1933 by Joseph Wallace (U.S. Patent Nº 1,907,626). Wallace’s description shows a section assembled from two pieces, one opaque and one clear, with an inner sleeve of a material that would not stain, preferably glass. He did try to protect the basic concept, however, by stating that the section could be made as a single piece.

Virtually every maker of sac-filling pens jumped on the bandwagon with this simple innovation, implementing it in different ways to circumvent Wallace’s patent. Sheaffer even used the feature to tout the advantages of its lever fillers, advertising that the pens were Visulated (Visible+insulated) whereas the competition’s pens (the Parker Vacumatic!) were not insulated against the heat of the user’s hand. (Sheaffer did not fail to point out, though, that it also offered its pens with the Vacuum-Fil system for those who preferred that design.) Parker marketed its version of the Wallace section as the Visometer Ink Supply. Here are a Sheaffer’s Balance Valiant and a Parker Parkette with Wallace-type sections:

Fountain pen Magnifying glass
Fountain pen Magnifying glass

With their two Big Four competitors locked head to head using Wallace-type sections, Wahl-Eversharp and Waterman took another approach, moving the transparent area up the pen to the space just aft of the barrel threads. This concept also came from the fertile brain of Joseph Wallace (U.S. Patent Nº 1,943,048), but again the implementations were different from his version. Where Wallace posited a clear celluloid barrel area with a sleeve of glass attached to the inside of the barrel (making no provision for a sac), both companies created the “sleeve” as a clear celluloid extension of the section, long enough to align with the barrel’s clear band. (This “sleeve” could, and did, become stained.) Unlike other pens of the time (e.g., the Conklin Nozac and virtually all German piston fillers), these pens do not have clear barrel threads; the clear area is actually a narrow band between two colored areas. Here are a vest-pocket Eversharp Doric and a Waterman (unknown model), both made in about 1935:

Fountain pen Magnifying glass
Fountain pen Magnifying glass

War Gets in the Way, But You Can Still See the Light

During World War II, with rubber severely rationed, cheap pens with syringe fillers appeared in relatively great numbers. These cheap pens were made along traditional lines, with the front half of the barrel forming the ink reservoir and the back half forming a blind cap that screws off to expose the plunger in the same manner as in the Post pens of earlier decades. Here is a DU-PONT pen, whose hard rubber section makes it much easier to repair than most others, which were fitted with celluloid sections fused to their barrels. This pen has a modern Pelikan M200 nib with plating removed from the tines to match the original DURIUM TIPPED nib’s design.

Fountain pen Magnifying glass
Fountain pen Magnifying glass
Fountain pen Magnifying glass

I Can See Clearly Now

Fountain pen feedAfter World War II, the fashion for visible ink supplies faded, possibly for stylistic reasons and possibly because of the rise of polystyrene as the principal replacement for celluloid in pen bodies. By 1948, Sheaffer had discontinued the visible ink-supply feature in pen bodies entirely as part of its switch from celluloid (Radite) to an injection-moldable cellulosic resin that it called Radite II; but there was now a Visulated section. The Parker Vacumatic, long in the tooth, hung on until 1948, but the new Parker VS was made of Lucite™, like the “51”, and was opaque. But at its 1946 introduction, the VS had a clear Lucite feed (shown to the right) that allowed the user at least a glimpse of the ink supply. (The Lucite feed disappeared in the first quarter of 1947, replaced by the old reliable hard rubber.) Here are a 1948 Sheaffer Crest Tuckaway in Radite II and a 1946 Parker VS:

Fountain pen Magnifying glass
Fountain pen Magnifying glass

But other companies that had followed Parker’s lead and introduced their own transparent feeds did not discontinue the feature quite so quickly. Wearever and Tuckersharpe were making pens well into the 1950s using injection-molded clear plastic feeds. Shown here is a Wearever Zenith; you can see the clear feed through the nib’s breather hole (see the zoomed image for a clearer view).

Fountain pen Magnifying glass

Hide and Seek

By 1948, the visible ink supply feature was essentially passé; the world had moved on. But even when you’re making a pen with an ostensibly non-visible ink supply, sometimes you can still make the ink supply visible (even if you hide it), and this is what Parker did with the Pli-Glass sac in its Aero-metric “51”. Users had to remove the barrel to see whether their “51”s were about to run dry, but at least there was that modicum of last-ditch comfort. Shown here is an unused Parker “51” Mark III body with the barrel removed to reveal the filler:

Fountain pen Magnifying glass

When All Is Said and Done…

What we have today, in 95 of 100 pens, is a visible ink supply that is provided by the transparent materials of which converters and most cartridges are made. If you ask the average pen user whether being able to see the ink supply is a good thing, the answer will probably be, “I like it that way.” Which, in all likelihood, was the answer that pen manufacturers got when they started this whole thing a century ago. Truly, there is nothing new under the sun. Shown here is the section from a Conway Stewart Duro Heritage, with a standard converter in place.

Fountain pen with converter Magnifying glass

The variety of designs that engineers came up with to provide the user with a way to see the ink before it goes onto the paper, not after it fails to do so, could form the focus of a very interesting pen collection.


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