(This page revised March 17, 2022)
|This April 1942 Parker “51” ad proclaims, “YEARS AHEAD OF ITS TIME. For 11 years past, chemists and engineers have been collaborating to produce the writing masterpiece — a pen made for a ‘high velocity’ ink — the “high velocity’ ink made for the pen.”|
The Fabulous “51”: When it introduced the “51” in 1941, the George S. Parker Company knew it had a winner. The pen was stylish but not flashy, durable but not clunky, and reliable but not overengineered. The pen shown below is a first-year model with a simply styled Lustraloy (brushed stainless steel) cap that modern collectors have dubbed “Wedding Band.”
Over the next 31 years, the pen proved itself immensely popular. Tales are told of people who, unable to afford a whole pen, would purchase only a cap to clip in a pocket, giving the appearance of a complete pen. Parker discontinued the “51” in 1972, but “unofficial” production continued into the 1980s in Argentina, using machinery that Parker had abandoned. Parker is believed to have sold between 20 and 50 million “51”s; the exact number is not known because the company apparently stopped counting after the first 12 million.
A Note on Punctuation
Parker’s trademark for the original “51” included quotation marks as used throughout this article. As registered, the trademark for the 51 SE (a limited run produced in 2002) and the 51 and 51 Deluxe (introduced 2021) does not include the quotation marks, although Parker did include them in the barrel imprint on the 51 SE. These latter models are discussed later in this article.
Compared to many fountain pens, both its contemporaries and more recent models, the “51”, with its monochrome plastics and its tiny nib that lies hooded within a shell, might be considered a Plain Jane. But the “51” was not designed to be an eyecatching display piece. It was designed to be an everyday, hardworking, trouble-free, reliable writer.
Good engineering discipline dictates that form should follow function, and Parker’s engineers and stylists apparently followed that dictum. They applied the best available technology in the most effective way possible to perform the very difficult task of writing under virtually any conceivable conditions, and the result was U.S. Patent No 2,223,541, filed by Marlin S. Baker on January 6, 1939, and issued to him on December 3, 1940. The fact that so many Vacumatic-filling “51”s are still in use more than 60 years since the last one was produced is a testament to their success. 3D cutaway illustrations of the design of the “51” are given in Anatomy of a Fountain Pen IV: The Parker “51” (Aero-metric Version).
Baker’s patent, on the surface, reveals an ingenious approach to dealing with the problems confronting the pen’s design team. However, as brilliant as the design is, it was not entirely original. On June 7, 1937, an independent inventor named Russell T. Wing filed for protection on a design that covered the basic concepts of the hooded nib and ink collector, and on January 16, 1940, he received U.S. Patent No 2,187,528. Shown here are the key drawings from Wing’s (upper) and Baker’s (lower) patents.
In early 1938, Wing sold exclusive manufacturing rights to Parker for a 0.27% royalty (27¢ for every $100 of wholesale goods sold) on all future “51” sales, with a minimum payment of $5,000 for the first year and $8,000 per year after the first. During the 1940s, Wing developed further improvements. In 1943, he and Parker signed an agreement with Sheaffer, forestalling pending litigation for patent infringement, under which Sheaffer, for a payment of $25,000 and royalties, was granted a license to use the collector concept that it had embodied in the conical feed used with the “TRIUMPH” point and was excused from penalties for the pens it had already sold that used the concept. (Coincidently with the execution of this agreement, Wing and Parker added a rider to their original agreement reducing the minimum annual payment to $6,000 in consideration of the additional 0.27% royalty payments to come from Sheaffer.) In 1945, the agreement was extended to Sheaffer Canada, and in 1947 Wing and Parker entered into a similar agreement with Waterman, with Wing to receive 0.27% royalties from Waterman as well.
Conceived to write with Parker’s innovative super-fast-drying ink, which was also dubbed “51”, the pen was styled to accommodate its necessary innards while at the same time having a pleasing appearance. The illustration above shows a classic example of the styling: a 1948 black “51” with a Lustraloy Stacked Coin Band cap. This and a matte Lustraloy cap with a single narrow raised band were the only cap variations that had chrome-plated Blue Diamond clips.
The pen accomplishes that marriage with exquisite success. Unlike other pens of its time, including the Vacumatics that preceded it, it isn’t marbled, mottled, striated, or pearlescent. Also unlike other pens of the time, it was never offered in an imposing “oversize” version. The ”51” is smoothly streamlined and sized not to impress onlookers but rather for its ability to serve a broad spectrum of writers who could, would, and did use it, day in and day out, without having the luxury of changing pens three or four times a day on a whim. For the first six years of its existence, it came in one size only; not until 1947 did Parker make a model of a different size — and then only a shorter version, called the Demi. Here are a Vacumatic-filling “51” Demi and a standard “51”. The The Demi is clearly shorter, and it does have a shorter cap; but the difference in body size was taken all out of the barrel’s length, leaving the front and back ends — and the overall diameter — unchanged, resulting in a noticeably stubby appearance:
The metal cap exemplifies the pen’s advanced engineering. Embodying Parker’s proven and very attractive design for mounting a sturdy (and replaceable) clip, it slips smoothly and reliably over the shell to seat on the clutch ring (U.S. Patent No 2,278,907, by Marlin S. Baker) and then stays put in a way that was inconceivable to the makers of earlier hard-rubber slip caps. Unlike the celluloid caps of the pen’s 1940s competitors, it is split-proof, even when too forcibly installed, and it doesn’t gouge the surface of the shell. The cap is also attractive as well as practical: Parker offered it in several polished, brushed, and matte (“Lustraloy”) versions of stainless steel, as well as a bewildering array of precious-metal designs. Silver alone appeared in four different versions: polished sterling, lined sterling, hammered sterling, and coin silver. (Sterling is .925 fine, coin silver is .900 fine.) On Vacumatic-filling “51” pens with gold or gold-filled caps, the recessed area of the clutch ring is gold washed, giving an elegant two-tone appearance that complements the cap. Most gold-capped Aero-metric pens have plain stainless-steel clutch rings. Shown here is a Vacumatic-filling model in Cordovan Brown with a gold-filled cap with a “Feather,” or “Chevron,” band. For Cordovan Brown only, the end jewels were amber celluloid instead of the usual gray. On the cap are the stylized initials of the original owner, HFF:
Where did the name “51” come from? Parker completed the development of its new pen in 1939, the 51st year of the company’s existence. Rather than give the pen a name that might prove less than felicitous when translated into other languages, Parker began a decades-long tradition by choosing a number. Numbers do not require translation.
At its 1941 introduction, the “51” was placed at the top of Parker’s line, ousting the eight-year-old Vacumatic from that honored position, and it bore price tags beginning at $12.50. Like all other Parker pens priced at $8.75 and higher, the “51” was warranted for the purchaser’s lifetime and bore Parker’s Blue Diamond, the visible indication of that warranty. The first version used the Speedline version of Parker’s reliable Vacumatic filling system, with a jeweled blind cap (the double-jewel version of the “51”). Within the year, however, the United States entered World War II. The U.S. government designated certain materials, including aluminum and brass, as critical war resources. Parker redesigned the filler and the blind cap to save those metals for the war effort. Although Parker continued to produce double-jewel pens, those pens were the premier models in the “51” line, and they were made in far smaller numbers than the single-jewel version. Thus, the most common Vacumatic-filling “51”s today do not have the jeweled blind cap. (Certain colors, however, such as Nassau Green, are more common in the double-jewel version.) Shown here is a single-jewel pen that was presented to an employee as part of a factory-wide celebration in Janesville when Parker was presented with the Army-Navy "E" Award for production excellence on October 29, 1943:
1946 saw the introduction of Parker’s first attempt to retire the by-then ancient Vacumatic filler. In that year, along with the button-filling VS, the company brought out a new “51” that featured a spoon filler operated by a long-stroke button similar in appearance and action to the multistroke Vacumatic pump. One of the ways Parker reduced cost was to make the threaded collar that secures the filler of plastic, in a red color to distinguish it visually from the black-anodized metal collar of the Vacumatic version — an important distinction if the Vacumatic pen was fitted with the visually similar Speedline filler. When the plastic proved too fragile in real-world use, engineers replaced it with red-anodized aluminum. Because of the collar’s color, Parker designated this “51” model as the Red Band version, while the Vacumatic-filling “51” was called the Black Band version. Instruction sheets packaged with the pens while both were available referred to them by band color. For various reasons, the Red Band “51” was retired in 1947, making it one of Parker’s shortest lived pens, and it is today uncommon and highly collectible.
When Parker’s engineers finally did retire the Vacumatic filler, they did so only in favor of a more reliable one. Beginning in 1948 with the reduced-scale Slender (renamed the Demi after a couple of years), the “51” sported Parker’s new “Foto-Fill” system (U.S. Patent No 2,612,867), which provided improved performance at high altitude and was also easier to use. Shown below is an Aero-metric “51” Demi, with a standard Aero-metric “51” for comparison. In order to improve the Demi’s asethetics, Parker’s designers made the new version a little longer than the Vacumatic-filling Demi and a little thinner than the standard pen.
The original “51” sported a Blue Diamond clip that identified it as the rightful successor to the great Vacumatic. (After the U.S. Federal Trade Commission prohibited the offering of a warranty if a fee was charged unless the fee was described in type the same size as the warranty statement itself and in close proximity to it, Parker stopped painting the clip’s diamond blue.) With the changeover to the Foto-Fill system (soon renamed “Aero-metric”), the clip changed, too, to an arrow reminiscent of the one used on Vacumatics before the Blue Diamond made its appearance in 1939. There is more information, including illustrations, on “51” clip variations later in this article.
Kenneth S. Parker, son of company founder George S. Parker and longtime CEO, was fascinated by aircraft and flying. In early 1946, the company purchased a new corporate plane (shown below), a shiny aluminum Beechcraft D-18S with gold “feather” trim. The plane’s registration number, of course, was NC5151.
Photo © Geoffrey S. Parker; colorized by the author.
Used with permission.
The Beechcraft’s dramatic appearance inspired Kenneth to ask his designers for an airplane-like pen design. The result, an otherwise standard Aero-metric pen, was the famous stainless-steel Flighter, introduced in October 1949:
In 1961, Parker tried to extend its new cartridge/converter technology to the “51”. The resulting pen was withdrawn after only two model years. Thus, not very many cartridge/converter “51”s were made, and the model is something of a rare bird in the “51” world. Most collectors today think that the pen failed because Parker cheaped out by replacing the all-important ink collector with a solid block that didn’t produce the desired writing qualities, but in my experience this is not so. I suspect that the real problem may have been high assembly costs due to the lack of any internal provision for automatically aligning the nib and feed with the shell, such as was present in the 61.
The “51” may not be every collector’s cup of tea, but it is anything but ugly. “Ugly” does not sell more than 20 million pens over a span of more than 40 years, and “ugly” does not inspire a manufacturer to reprise a design that should, by the standards of most other industries, be dead and gone.
Over the years, many collectors have speculated that the “51” was designed by Bauhaus master László Moholy-Nagy, but he did not begin doing work for Parker until after the development of the “51” had been completed. Aesthetically speaking, the ”51” (U.S. Patents Nos D116,097 and D116,098, by Kenneth S. Parker and Marlin S. Baker) is in fact one of the most elegantly beautiful fountain pens ever made and, with its hooded nib and collector, quite probably the most revolutionary since Lewis Waterman’s discovery of the channeled feed. Certainly there has been no more truly remarkable pen since its inception.Dating a “51”
Pens made before Parker stopped date-coding its pens have a date code on the barrel. For instructions on reading this code, refer to Parker’s Date Coding Systems.
Pens made after Parker stopped using date codes (early to mid-1950s) cannot be dated to a particular year, but you can at least narrow the possible range of years. Except for a small number of cartridge/converter pens produced from 1961 to 1963, all of these undated pens are Aero-metric fillers, and Parker’s service manual describes three distinct models:
The most common Aero-metric “51” is the Mark I. Externally, this pen is identical to the Vacumatic-filling version except that the barrel no longer ends in a blind cap and that the Split Arrow clip is gone, replaced by the plainer Arrow clip:
The filler’s sac guard in a Mark I pen has a plastic end cap:
For about the first two years, the sac guard was made of polished chrome-plated aluminum and screwed onto the barrel connector. It instructed the user to press six times when filling. After that time, the part was made of brushed stainless steel and pressed into place, and it called for only four presses.
A subtlety to watch for is the filler of the “51” Demi. Early Slender pens, before the model was renamed the Demi, have fillers like that of the standard model but appropriately smaller; but later Demis, beginning probably in mid-1950, use the less costly “hoop” filler design introduced in 1948 on the “21”. As noted later, this filler design also appeared on the “51” Special; it therefore exists in two sizes:
At some point, probably in the late 1950s, Parker introduced a slight variation on the Mark I design. In this apparently undocumented “Mark Ia” version, the Aero-metric vent hole is moved from the end of the barrel to the side of the barrel, about of the way from the clutch ring to the end, possibly in an attempt to forestall the entry of pocket-bottom dust and lint that can clog a hole at the end of the barrel.
In about 1962, Parker began producing the Mark II “51”. This version, redesigned to update its look, bears a noticeable resemblance to the 61. Its cap has a 61-style clutch, with fingers bearing on the shell instead of on the clutch ring, but the standard “51” clip is still present. The end of the barrel is squared off to a shallow conical shape that mimics the cone of the cap jewel. Placing the barrel vent hole at the side of the barrel in the Mark Ia appears to have yielded no benefit; for the Mark II, the hole was restored to the end of the barrel.
Internally there are significant differences, as Parker redesigned the internal parts to simplify the sac guard and replace the costly machined collector and feed with molded plastic parts. The breather tube, formerly made of sterling silver, became rigid plastic tubing. The most noticeable internal change is in the sac guard, now a single piece of smooth stainless steel with its end formed closed instead of being capped by plastic:
The Mark III “51” appeared in about 1969. This pen looks similar to the Mark II. The cap shows the most visible external change. The clip, a new 61-style long Arrow clip, is no longer part of the cap’s decorative trim ring; it is a separate part. The trim ring and jewel are combined into a decorative clip screw that holds the clip in place as on the Parker 75. The clutch ring, which is not functional, is now reduced to a narrow trim ring. The most significant changes are not visible to the user:
No longer does the pen have the Aero-metric filling system. Instead, it has a short breather tube and is thus an ordinary squeeze filler like the “51” Special and the “21”.
The Mark III, unlike its predecessors, is made of an injection-moldable plastic, not Lucite. The new plastic is softer and will take scratches more readily; and it also can shrink over time.
The Mark III’s sac guard looks like that on the Mark II, but the trim ring identifies the later pen. You can also see on closer examination that the threads on the Mark III’s connector are rather coarser than those on earlier pens and that they have an Acme profile (flat on the crown and at the root).
Note that not all of the differences may be identifiable on any given pen; Parker phased some of the changes in rather than making a sudden 100% switch. The clip design of the Mark III is one example of this; there exist Mark III pens with the older design having a separate celluloid jewel.
In 1950, Parker introduced a reduced-cost version of the “51”. This “51” Special looks outwardly very much like a standard “51”, but it has a stainless-steel nib (called Octanium, from the total number of eight metals used in its manufacture) along with the hoop filler found in the “21” and the “51” Demi (illustrated above). The filler in the “51” Special, however, is larger than that in the other two models. Other cost-saving measures were a limited choice of colors (indicated in the table below), a bright-polished stainless-steel cap, and a black cap jewel.
Some later examples of the “51” Special have gold nibs. Tthis was probably not a move to improve the model, but rather to use up existing stock of gold nibs as the “51” line was retired.
When Parker introduced the “51” in the U.S.A. in 1941, the pen bore a “Split Arrow” clip. Because all Parker pens priced at $8.75 and higher were Blue Diamond models, it follows that the “51”, introduced at a price range beginning at $12.50, was also a Blue Diamond pen. All “Split Arrow” pens appear originally to have been Vacumatic fillers. (But the converse is not necessarily true, as we shall see later.) I have seen Blue Diamond clips with three different placements of the Blue Diamond itself. Note that the clip on left-hand cap shown here, with its Blue Diamond placed well below the shoulder, is actually correspondingly longer than later clips:
Most “Split Arrow” clips are gold filled. Another uncommon but not rare variant, however, is a chrome-plated Blue Diamond clip. This clip is found on coin silver caps, on brushed stainless steel Stacked Coin Band caps, and on matte Lustraloy caps with a single narrow raised band. Here is a chrome Blue Diamond clip, on the Stacked Coin cap from a 1947 pen:
An uncommon variant of the “Split Arrow” clip as applied to the “51” is like that of the Vacumatic Junior, without a Blue Diamond. Parker test-marketed the “51” between 1939 and 1941, and these pre-release pens bore this clip:
At various times, Parker applied the Blue Diamond either as opaque paint or as translucent enamel. Either form of the color could, and did, wear away. But there are almost always traces to indicate that it was there. Some “51”s appear from time to time with no trace of blue on their “Blue Diamond” clips; it appears that Parker sold “51”s with the diamond not colored blue after the FTC’s final ruling regarding lifetime warranties:
In 1947, with the introduction of the Vacumatic-filling “51” Demi and continuing into 1948 and the transition of all “51” models to the new Aero-metric filling system, Parker reintroduced a slightly updated version of the old Art Deco clip. The redesigned clip was a virtual duplicate of the Art Deco Arrow clip that had first appeared on the Vacumatic from 1933 to 1938. (The essential difference is that the mounting ring on the ”51” version has a smooth curve without the ridges of the Vacumatic version.) The new Arrow clip was made in gold filled and chrome plated versions. Color aside, there are two variants of the Arrow clip, as shown in this picture:
When Parker reintroduced the Arrow clip, it was the longer version shown to the right above. The company may have begun using the long Arrow clip sometime around the end of 1946; this means that Vacumatic-filling full-size “51”s with long Arrow clips are therefore not necessarily the product of cap swapping.
Very early in the 1950s, the clip lost some length (left, above). In the mid-1960s, Parker restyled the ”51” to create the Mark II variant, giving it a new cap like that on the 61, but still with the short ”51” clip. In about 1969, the ”51” Mark III appeared with a new 61-style clip, longer even than the older long ”51” clips and attached in the same fashion as the clip on the 75, and the venerable ”51” bore this clip until it was discontinued. The image below shows Mark II (left) and Mark III (right) clips:
The ”51” is today one of the most popular collectible fountain pens, and its popularity led Parker in 2002 to produce a limited-run pen, called the 51 Special Edition (51 SE), which looked outwardly like a double-jewel Vacumatic-filling “51” with an Empire cap but was internally different, with a cartridge/converter filling system and an ink delivery system identical to that of the Parker 45. The 51 SE (below, upper) was available in only two colors, Vista Blue with a sterling silver cap and black with the same cap partially gold plated. The plastic used for the barrel and shell of the 51 SE, especially the Vista Blue color, is so notorious for cracking that it has been described as having a “self shattering” feature.
In 2021, Parker struck again with the 51 and 51 Deluxe (Deluxe shown below, lower), which are cartridge/converter fillers with threaded caps and an ink delivery system that is essentially the same as the open nib and feed in ordinary modern fountain pens.
|51 Deluxe photo © Parker Pen Company. Used under U.S. Fair Use copyright provision.|
Parker’s own efforts notwithstanding, the best testament to the longevity of the “51” design comes from China, where several companies have produced pen models patterned on the “51”. The pens shown below are a Hero 616 (Aero-metric filler), a Wing Sung 601 (modified Vacumatic filler), and a Jinhao 85 (modeled on the modern 51, with cartridge/converter filling.
None of these pens is an exact copy of a Parker model. All are descended from China’s 1948 nationalization of Parker assets in Shanghai, which created the Shanghai Hero Pen Company.
In addition to the various Chinese copies, which have some degree of legitimacy, copies were made elsewhere without Parker’s approval.
In the Soviet Union, Leningrad’s Soyuz factory produced several models, including the top-line Moscow (shown below) and the Leningrad, both accordion-fillers. The Moscow’s cap-crown jewel and the mall red jewel at the top of the Kremlin’s Spasskaya bashnya (Saviour tower) on the back side of the cap are faceted garnets.
In the years after World War II, several small pen makers in Settimo Torinese, Italy, had a field day marketing counterfeit Parker “51” pens to the tourist trade; this activity was finally shut down by the Italian government.
A Coat of Many Colors, One by One
The “51” Vacumatic, Aero-metric Mark I, and Aero-metric Mark II versions are made of DuPont Lucite, an acrylic plastic that is remarkably tough and was in 1941 the very latest leap in materials technology as well as being the only plastic then available that could withstand the corrosive effects of ”51” ink (which was itself a market requirement). The plastic isn’t marbled, striated, or otherwise variegated because in 1941 nobody knew how to do those things with acrylics. Although the ”51” had no interestingly patterned plastics, the model was made in a great many colors. The colors listed on this page are divided into four groups: those of the Vacumatic-filling “51” from 1941 to 1948, those of the Aero-metric-filling “51” from 1948 to the 1969 introduction of the Mark III, those of the Mark III from 1969 to the end of the model run in 1972, and the metals that appeared on Aero-metric pens. Most of the Vacumatic colors varied from lot to lot, and some pens are now showing discoloration due to age; thus, any two pens — or even the several parts of any given pen — can have markedly different hues or shades. The pen shown here, in the highly desirable Nassau Green, shows a rare perfect color match between its shell, barrel, and blind cap:
The Rage Red and Vista Blue colors were used primarily on the Parker 61, but the Mark III “51” was test marketed in these colors. The 51 SE was offered only in Vista Blue or black. Rumors persist of a different purple and another blue/green color. There were also the stainless-steel Flighter; a gold-filled model called the Signet; and a solid gold version, the Presidential.
Parker also made demonstrators for use by dealers in explaining the pen’s internal construction. The first-year “51” demonstrator, made in 1941, had a clear shell and a red collector, with a black barrel; this color choice emphasized the important features that set the “51” apart from all other fountain pens of the time. The black barrel de-emphasized the Vacumatic filler, which had been on the market for eight years and was certainly not considered novel. Later demonstrators, as shown here, were entirely clear:
The top pen here is a 1941 (first year) demonstrator. Note the red collector. (The gold-filled cap is not original to this pen.) The middle pen, with a clear barrel, was made in 1948. The bottom pen is an Aero-metric demonstrator with no date code, made probably after 1952.
|Colors of the Vacumatic Filling “51” (1941–1948)|
|Color||Name (Factory Color Code)|
|India Black (11)|
|Dove Gray (01)|
|Burgundy (14) — extremely rare; appears on a very small number of U.S.-made pens|
|Cordovan Brown (03)|
|Buckskin Beige (“Tan”) (97)|
|Yellowstone (“Mustard”) (96)|
|Nassau Green (98)|
|Navy Gray (13) — official color in Australia; appears on a small number of U.S.-made pens|
|Blue Cedar (02)|
|Colors of the Aero-metric Filling “51” Mk I and Mk II (1948–1969)|
|Color||Name (Factory Color Code)|
|“Blood Red” — appears on pens made in the U.K.|
|Forest Green (12)|
|Navy Gray (13)|
|Teal Blue (26)|
|Midnight Blue (15)|
|Plum (08) — Mk I only|
|Colors of the Squeeze Filling “51” Mk III (1969–1972)|
|Color||Name (Factory Color Code)|
|Rage Red (23)|
|Navy Gray (13)|
|Vista Blue (35)|
|Dark Blue (16)|
|“51” Metals (not used on Vacumatic models)|
|Brushed Stainless Steel (Flighter)|
|Gold Filled, with Grouped Lines (Signet)|
|Gold, Plain (Presidential)|
The information regarding the percentage of the royalty came from Wing himself, in a personal conversation with a person known to me. The remainder of the information in this paragraph is drawn from court documents in the case of Russell T. Wing and Zoe E. Wing, Petitioners, v. Commissioner of Internal Revenue, Respondent (United States Court of Appeals, Eighth Circuit, Case Number 278 F.2d 656, June 2, 1960).
For the technically minded, “51” ink (U.S. Patent No 1,932,248) did not actually dry rapidly. Its chemistry, which included metallic salts and sodium hydroxide (lye), caused the ink to sink into the paper so rapidly that the ink would appear to have dried in about one-half the usual drying time of contemporaneous inks.
The FTC’s original 1945 ruling forbade “unconditional” warranties altogether if there was a fee. L. E. Waterman and Parker challenged the ruling, but Waterman withdrew its petition in 1946. Parker fought on, and the resulting 1948 court judgment softened the ruling, allowing such warranties if the fee was described in type the same size as the warranty statement itself and in close proximity to it. (The prohibition remained on the use of the word “unconditional.”)
Color codes are taken from wall-mounted cards used by the Parker factory repair department in Janesville, Wisconsin. Although Charcoal and Olive are listed on those cards, I have not personally seen any pens in either of these colors.
Although Burgundy and Navy Gray are not commonly thought to be official U.S. production colors, they are listed on the factory card from which the color codes are taken. It is possible that they were produced in small quantities as a test run as Parker prepared to introduce the Aero-metric “51”. I have seen no pens in these colors that bear date codes.
The information in this article is as accurate as possible, but you should not take it as absolutely authoritative or complete. If you have additions or corrections to this page, please consider sharing them with us to improve the accuracy of our information. Color code information provided by Susan Wirth.