The Cap that Can’t Leak, consists of a Parker Jack-Knife Safety double cap, one inside the other. The outside cap «A» screws on the barrel in an ordinary way. «B», the inside cap, screws into the outside cap, the top extending out of the end of the outside cap. After the outside cap is in position, an extra turn on the protruding inside cap forces the outside cap tight against a special shoulder of the barrel, enclosing the pen in an ink-tight chamber. The air pressure in this chamber prevents a flow of ink from the pen point, even although the pen is carried upside down. Even if the ink does escape, it cannot get into the outside cap, or smear the nozzle of the pen. You will always find the Parker Jack-Knife Safety ready to write at the first stroke, flowing freely and evenly.
The Jack-Knife Safeties were Parker’s entry into the safety pen market. It was protected by patent US1,028,382, filled in 1909 and granted in 1912.
The model line was the mainstay of the product line throughout years 10’s and, in the early 1920s, until 1922 in which the JKS 26 model became the Duofold that would revitalize Parker sales and be the beginning of the standardization and reduction in the number of styles and models in its catalog although, after Duofold, Parker continued offering Jack-Knife-style pens.
In a 1909 ad, Parker introduced this fountain pen so: “Something new and novel, yet a business-like safety pen. A short, efficient, attractive fountain pen that you may carry anywhere you carry your jackknife. Put it in your vest pocket, upside down -any old way- throw it in your grip or handbag, without fear of its leaking. The ideal pen for a lady to carry in her handbag.”
The July 1909 edition of Side Talks shows the Jack-Knife with a turban top but still shows a conical section. The nozzle of the pen was made a trifle wider than in the regular pen and with a flat facing. The cap was fitted with a secondary cap which has a thread on same and which turns easily inside the regular cap.
We would have to wait a few months to find the Jack Knife with its particular cup silhouette section.
In January 1910, the Jack-Knife line was out and running. It was now available in plain black, chased black – except the baby size-, plain mottled or furnished in red rubber when specially ordered. Likewise, any of the safety pens in black except the baby size No. 20 could be supplied with chased if desired.
The JKS series was made of hard rubber. The series 2X are plain surface holder, while 2X½ were chased. The fraction 1/2 following the model number denotes a pen holder chased.
Most of the Jack Knife fountain pens that have arrived at our collections are black hard rubber. Less frequently it was manufactured in mottled and, much more infrequent, in red, so red Jack-Knife nets are extremely difficult to find.
The JKS 2X series was just a size designation of the Parker product line, so for a higher model number, the greater the pen circumference. Number 20 was the narrowest, followed by the 24, 25, 26, 28, and then the Giants. The model 23 had the same diameter as the 20 basically but mounting a point #3 in place of #2 furnished with model 20.
Since its inception, the Jack-Knife models could be fitted with fancy mountings at special prices, if it were desired. Any Jack Knife pen could be trimmed with one or two gold bands by adding 50c at the regular price for a gold band and $1.00 for two gold bands.
In addition to pen 25c. extra (75c. gold plated and 5.00 solid gold) all Parker Jack-Knife safety caps could be fitted with a little ring fastened to the end of the cap so it may be suspended by a chain. Parker distinguished these variants with the initials S.R. because of their «Screw Ring».
By January 1910, the Jack-Knife line was off and running. It was available in plain black, black chased, and mottled hard rubber, with one or two gold bands. All models were available in a regular-sized and baby size, from models #20 to #25
At the same time, the Jack-Knife #15 and #45 could be ordered. The #15 had mother-of-pearl and/or abalone covered the barrel with gold-filled filigree on the cap, and #45 offered the same covered barrel, a smooth rubber cap, and a selection of faceted semi-precious stone, cabochon, or pearl imitation as a cap crown. Completed the JKS 1910 catalog the filigree models #14 and #16, sterling silver and rolled gold, respectively.
In December 1911, the Jack-Knife Safety #48, an overlay pen filled with gold with lined pursuit, was introduced. In this year was cataloged Jack Knife Safety #49 furnished overlay 18 k. gold cap and barrel with deep lines engraved effect and beautiful floral designs on top and bottom. It was $10.00. There are two versions; no. 48 without engraving chased on its holder for $8.00 and no. 55, same as this but finished in silver at $7.00.
Likewise, in 1912 long full-length pens were added to the line. Parker presented it like this: “Last year many of our friends asked us to make the Jack-Knife Safety with a full-length barrel, due to many customers who wanted to carry them upright in their pocket and yet they have the safety function. We have done this now.”
The JKS models arrived in four lengths: a long full-length, usually 130-135 mm., a regular about 110-115 mm., the Baby model for 100-105 mm vest pocket wear, and an uncatalogued smaller Baby of approximately 90 mm. long.
Towards the second half of 1912, the cup-shaped nozzle gave way to a more standardized section. In August 1913, in a Saturday Evening Post post, we saw for first time a most standard nozzle/section.
In 1913, Parker began producing the new «press the button» self-filling that replaced the «click-filler».
With the arrival of this button self-filler, the Jack-Knife Safety series was redesigned. The «turban» cap end was replaced by a flat-top-style (the same of Duofolds over time), and the Jack-Knife was available as a button self-filling.
1914 was a great year for new products from Parker, so at the beginning of the year, they introduce the PARKER BAKELITE Pen, a wonderful pen which the barrel looks like clear amber and through which may be seen the ink these barrels also extended JKS style although they are quite scarce. Parker developed three colors in Bakelite; a shade green, and two shades of red and pink.
Jack-Knife regular pens filled with eyedroppers continued to be produced, being its production cataloged until 1923.
Parker added Jack-Knife versions to practically all its models, so at that time JKS was responsible for most of Parker’s businesses.
In 1914 Parker filled patent for a new and innovative washer clip. This new Parker clip long or medium length barrel would be offered in German silver nickeled at 25c extra. Gold plated was 75 c., and solid gold was $5.00.
In 1916, Parker introduced the collapsible no. 70 eyedropper, a new shaped Parker Jack-Knife gold-filled especially designed for a graduation, present, or birthday gift.
In the same year, inspired by the Jack Knife self-filler, introduced Ivorine, a small, colorful pen focused on the ladies’ market as target.
The Parker Trench, an eyedropper pen with a long end cap intended to hold ink tablets, released in 1918 was also supplied with a Safety cap. In the same year models #26 and #28 was catalogued as a Jack Knife pen.
In 1920, a new factory, costing $375.000, was built and completed on the corner of Court and South Division Streets.
With the Duofold arrival in 1922, Parker continued to offer Jack-Knife-style pens.
In the second half of 1923, with the success of the new Duofold verified, the company reduced the Jack-Knife line and presented them as a new style of a pen which it had given the moniker «Parker D.Q.» -meaning Duofold Quality. This pen, in two models, for men and women, sells for $3.00, less than half the price of a Duofold Senior. It was a black rubber pen, with distinctive chasing, designed for that marker that wants a pen «Duofold» quality but less than the Duofold price.
By 1925 the «DQ» model was renamed as «Parker Black and Gold» pens in black hard rubber. In 1930, when this series was manufactured in Permanite celluloid and streamlined silhouette they were known as Raven Black and Gold. Together, these fountain pens are known as the «Black Lines».
Parker’s safety principle would continue with the double cap that also features the Vacumatic pens.
- 1914/1918 and 1922 Parker catalogs.
- 1909/1922 Parker SideTalks and Parkergrams, the Parker´s dealer magazine.
- Sorgatz, L. (February, 1994) «A History of the Parker Jack-Knife Safety Pen.» The Pennant magazine, Vol VIII, nº 2.
- Fountain Pen and Pencil. The Golden Age of Writing Instruments. G. Fischler & S. Schneider. Ed. Schiffer Publishing, Ltd. 1990.
- Plumas Estilográficas. Jonathan Steinberg. Ed. Edimat Libros. 1998.
- Tsachi Mitsenmacher pens collection.
- Luiz Leite pens collection.
- L. Michael Fultz collection.
- John Danza collection.
- 900 Parker ads. Pre-Duofold.
- Parker Safety patent US 1,028,382.