The Duofold Pencil

The Duofold Pencil

This article is a brief summary related to the pencil Duofold introduced by Parker between 1923 and 1928, the so-called Flat Top. To be described here are the diverse sizes, with the date of introduction in the market, the type of materials used in manufacturing, and the colors in which the pencils were offered. In subsequent articles, the Pre Duofold and the Post Duofold Flat Top pencils will be described.

The company Parker was founded in 1888 and began by making fountain pens exclusively, however, around 1918- 1920 it added the production of pencils in different sizes molded in bronze, silver, gold, and other metal combinations. These first pencils are very similar to the future pencil Duofold, but they are not imprinted with the name Duofold on the pencil, nor are so designated in catalogs or adds of the period.

In fact, the Duofold name appeared for the first time on a fountain pen produced by Parker in 1921 at the insistence of a salesman, Lewis Tebbel of Washington State. For reasons undetermined, George Parker was initially against the manufacture of this pen and ordered to stop production, nevertheless, the Duofold was the pen that saved Parker from bankruptcy. This first Duofold fountain pen is of a color called “maroon” by Parker, but now it is known as red-orange.

The first pencil with the Duofold name

The first pencil with the Duofold name was presented to the public on February 1st, 1923 and it was geared as a very appropriate graduation gift for University students, the advertisement offered the pencil as a Duette with the matching fountain pen. This 1923 pencil measures 11,8 centimeters in length, the body is in bronze finished with red-orange enamel, although a few are in black enamel; the cap is of metal electroplated in gold and is imprinted with the Duofold name; the clip is welded to the cap, and its shape resembles a spoon. The mechanism is of rotation, and one must take care when removing the mechanism because it has a certain type of coils and hooks that not knowing how they are intended to work can produce irreparable damage to the mechanism.

Three of the first Duofold pencils from my collection are shown in the photo.

Second pencil Duofold and the first made of Ebonite

This pencil was introduced by Parker in 1924 and it was made in red or black ebonite like the pens; it is larger in size than the pencil of the previous year, actually is of the same size as the next to be produced pencils that would be called “senior”. The imprint on the body says Duofold – Parker “Big Bro” Pencil- Janesville, Wisconsin USA. The cap is finished with three rings, two with sawed marks while the third is smooth; the clip is loose and finished in a ball, a feature to become standard for all later models. The mechanism is also of rotation but with improvements to facilitate repairs. I have shown these pencils to several collectors who remain surprised since they did not think that the pencils were genuine until I show them the vintage ad with a photo of the pencil. This pencil must have been in production for a short period of time because there are not many around; in my collection, I have eleven, nine of red ebonite and two of the black ebonite.

Caps of the pencil Duofold

The caps of the Duofold pencils have different shapes, due surely to variations introduced in the place of their production because Parker had factories in Canada and England in addition to the USA plant in Janesville-Wisconsin. Five different caps are in existence: the first Duofold pencil in bronze with the spoon-shaped clip welded to the cap; the subsequent Duofold larger pencil in ebonite with three rings in the cap and loose clip ended in a ball; and three others, one with long cap and a loose clip that keeps in place by the pressure of the body and the cap, another one also with the long cap but bearing a grove where the clip is inserted, and, finally still another with short cap and loose clip.

It should be noticed that the cap of the feminine Lady model does not have a clip but instead is topped by a ring for the passage of a silk cord that would allow carrying the pencil like a necklace or as a bracelet.

Sizes of Duofold pencils

The pencil Duofold Flat Top was offered in three sizes

Senior, 14,12875 cm (5 inches and 9/16)
Junior, 12,85875 cm (5 inches and 1/16)
Lady, 12,065 cm (4 inches and 3/4).

Colors of Duofold pencils

The colors, always related to the manufacture materials, were offered to the public approximately in this order: enamel orange (“maroon”) on bronze 1923; ebonite black 1923; ebonite red 1923/1924; and finally plastic (“permanent” made by DuPont) in black 1925; red 1925; green 1927; mandarin yellow 1927; lapis lazuli (blue grained) 1927; black and pearl 1928.

All these pencils also have matching pens in similar colors, unfortunately, the colors of the pens have deteriorated as a result of the chemical influence of the ink contained in their rubber sacs.

Pencil Duofold Lady in pastel colors

In May of 1925, Parker began to send to his salesmen a new line of pens and pencils of the Lady model in six pastel colors: magenta, gray/beige (the rarest one to find), violet, green apple, coral, and blue Naples. These pastels colors were also manufactured in a moire pattern. And because these pastel colors were only made for ladies, its advertisement was limited to women’s magazines.

Pencil and pens of the so call Duofold Quality (D.Q.)

Parker embarked briefly in 1924 in a production line of pens and pencils of quality similar to the Duofold line but of lesser price for use by children and young students in high schools (in fact, Parker was finishing the leftover black ebonite of the previous series already discontinued). These are the Parkers D.Q. (Duofold Quality), only in black, with a design of horizontal lines and the name of the company prominently imprinted in the body.

Note: All the pencils displayed are from the author’s collection.


Jimmie Cockburn was born in Lima, Peru, studied Medicine in Spain, and received the Extraordinary Prize of the Real Academy of Medicine for his doctoral thesis. He continued medical studies in Paris, France, and in the U.S.A. in the specialty of Anatomic Pathology and Laboratory Medicine receiving certification by the corresponding Boards of these specialties. He practiced Pathology covering three hospitals in the Southern Maryland area. He has retired since and now devotes part of his time to the collection of pens and pencils. His new specialty now is mechanical pencils, with a collection of several hundred units. You can visit his website at

This article was originally published in Spanish in La Gaceta del Club de La Escritura in January 2002. Check out Actionable acrylic paint tips you should know.



Without reservation, this book now stands as the definitive reference source on the Parker “51” the world’s most successful fountain pen.

David and Mark Shepherd have a passion for the Parker “51” which started with David’s use of the “51” in his schooldays and today has built up a collection that is one of the most comprehensive in the world. During his collection process, he has acquired substantial expertise in the subject which provided the impetus to write this book. As a retired Dentist in England, he is fortunate to have had privileged access to the Parker archives at the Parker Pen Co Ltd in Newhaven. David’s son Mark became involved in this project after graduating from Oxford University and starting work as a solicitor in London, spending much time researching the archives and helping to shape the structure of the book. Mark’s input into this book has been invaluable and he is also responsible for the extensive photography.

The “51” fountain pen was originally Kenneth Parker’s idea. As Geoffrey and Steven Parker, grandsons of Kenneth Parker, a state in the Foreward of this book “To us, the “51” is Kenneth Parker…and looking at a “51” today always brings him to mind.

The contents of this book, with many never before seen materials from deep within the Parker archives, is a journey along with Kenneth Parker, his design team of mechanical engineer Marlin Baker, patent attorney Ivan Tefft, and metallurgist Milton Robert Pincus. David Shepherd now documents the chronology of the “51” which actually started in 1928 with Parker’s desire to get into the ink business by developing a quick-drying ink. The ink was strongly alkaline, a new pen material was needed, and along came DuPont Pontalite, later renamed Lucite. The book now takes off as a 13-year adventure of research and development trials and successes to develop a pen unlike anything ever produced before or since. The final design was one of some complexity, with the pen’s 23 separate components requiring 238 different operations to manufacture, 42 of which were done by hand-produced to a tolerance of one-thousandth of an inch. Yes, the book almost reads like a novel, with the highly detailed structure of every development in manufacture and marketing almost every page has a startling discovery that finally sees the light of day.

The structure of the story begins with the history of the beginnings, the very root of design tracing to the first button filler of 1914. David explains and well illustrates with original designs and photos of developmental models and concepts. Illustrated are the major components of the product and detailed information on early test marketing, which was cleverly conducted in faraway markets of South America out of the glaring eye of the American markets in case of failure or disappointing results. Fundamental problems were identified, such as with the ink collector design. Continuing, David documents the evolution of the design from First Year Vacumatic filler, to American, English, and Canadian production. The mystery of the infamous Red Band filling system is finally fully explained, in part as a result of the huge garage sale lots found by pen collector Roger Cromwell a few years ago, containing perfectly preserved pens and parts belonging to a former Parker metallurgist.

“Glancing out his office window one day, Kenneth Parker noticed a marker sign on the highway running beside the Janesville factory. It read U.S. 51. On a business trip to New York he dined at Toots Shor’s restaurant, he noticed the address on the menu…51 West 51 Street. He decided on a name.”

The story continues with elaborate illustration and text concerning metamorphosis from Vacumatic to Aerometric fillers, the Demi size “51”, Liquid Lead pencils, ballpoints, and the desk pens continuing up to the 2002 Special Edition model. David and Mark document the great variety of style designs, aluminum and plastic jewels, prototype colors and cap designs both original and modern, prototype nibs and fillers, clips, inks, and some really strange-looking demonstrators.
Also illustrated is a huge variety of packaging and gift boxing, dealer point of purchase displays, and sales techniques are also explained. Almost everything documented in this book is new information that has never been disclosed before.

Did you know there was a “51” nib made in Arabic medium and broad, plus a broad music stub?
Prototype nibs included a three-way slit, a flat pointed nib, a totally flat and layered top, and bottom nib, and most outrageous, an experimental rubber-coated nib.

Furthering the great value of this simple yet complex pen is the role played by the “51” in world-historical moments. In 1941 the saga of Parker “51” manufacturing switched almost immediately after the introduction to war production efforts and the products they made. Advertising documented the use by famous individuals in peace and wartime, by Presidents, Generals, and world-famous personalities. The influence of post-war aviation, increased public transportation made the development of the high altitude leak-proof Flighter. This was “AA-1 priority” as Kenneth Parker would state. Post-war aviation demanded the next level of development for the traveling public and Parker created a design concept copied by almost every major pen manufacturer.

David and Mark conclude the book with extensive provenance, dating by barrel imprints, cap designs, anatomy drawings, key dates, valuations, and price guidelines. Extremely well researched and written with stunning photography this book is now the icon of Parker’s “51” reference. Adding to the value is an elaborate Glossary and Index making for easy quick reference, a chronology of key dates, and even has an illustrated Parker family tree. I can certainly say this was a wonderful discovery for me to read and highly recommend this as a choice book for any pen collector, modern or vintage. I would even say that after reading this book you can easily slip into any conversation with serious “51” collectors and have as much or more information for a knowledgeable discussion. The value of information far exceeds the modest $80. retail price making this book an easy reach for any serious or even casual pen collector.

Parker “51”
Hardcover, 169 pages, 8 ½” x 11”, dust jacket, full-color illustrations, index, and glossary.
Available worldwide.

David Shepherd will attend the 2005 Chicago Pen Show and autograph his books.

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Care and Feeding: How to Replace a Pen Sac

Care and Feeding: How to Replace a Pen Sac

Although I’m in the business of repairing and restoring fountain pens, I’d be silly to ignore the fact that some collectors are eager not only to use but also to maintain and even repair their pens. Replacing a leaking, ossified, or otherwise dead sac is among the simplest and most straightforward repairs you can make, and I know from experience that it’s tremendously satisfying to start with a pen that won’t take ink and end with one that does. This article, then, is my way of sharing that pleasure with you.

It’s always a good idea to learn by practice rather than waiting until a precious pen is on the line. To this end, I suggest you buy a couple of cheap pens on eBay or at your local flea market or antique mall to teach yourself the ropes before you turn your attention to your minty red ripple Waterman’s Ideal No. 7 with the Blue nib. Arnold, Wearever, Epenco, and Tuckersharpe are some cheap names to look for, and there are countless no-name junkers that go for less than $10.00. (I use the term “junkers” loosely, as you already know if you’ve read Don Fluckinger’s recent Extra Fine Points series on these pens.) If you get pens that have sacs, you can easily rip ’em out. This, too, is part of learning to resaca pen.

Tools and Supplies

First, you need a supply of sacs. No problem. Shown here, from top to bottom, are No. 13, No. 16 (latex and silicone), and No. 22 straight sacs. At the bottom, for reference, are a Debutante Vacumatic diaphragm and a standard Waterman Ink-Vue sac.

My sac vendors of choice are the Pen Sac Company and Wood Bin Ltd. (Contact information for all the suppliers I mention is at the end of this article.) The Pen Sac Company sells a bewildering variety of straight sacs, necked sacs, tapered sacs, Ink-Vue sacs, and Vacumatic diaphragms. (“Diaphragm” is what Parker called the rubber doohickey in a Vacumatic so they could advertise the pen as being sacless.) They offer a couple of assortments as well as individual sacs. Their catalog includes several pages of information showing which sacs go into which pens. (There may be exceptions on a per-pen basis; the catalog says to use a No. 21 necked sac for a hard-rubber Duofold Junior, but I couldn’t even get a No. 20 to fit into the barrel of a Junior I resacked some time ago.) Wood Bin Ltd offers a smaller variety, but Wood Bin also sells straight sacs made of silicone. Silicone is sometimes a better choice than latex because it doesn’t outgas sulfur vapor that can cause some celluloid to turn brown.

You can also buy sacs from Fountain Pen Hospital, Pandemonium, and others; and Pen Sac Company and Wood Bin Ltd will of course be happy to sell you one or two sacs.

Next, you need sac cement. Some pen suppliers can sell you sac cement; several of the vendors I list here offer small bottles with an applicator brush for about $5.00. Being a professional cheapskate, I ran down to my local paint store and handed over about five bucks for a half-pint can of orange shellac, which is what the pen companies themselves used. I have enough shellac to last until my 273rd birthday. On the other hand, I don’t have that nice applicator brush, so I have to resort to subterfuge. I use toothpicks.

Steal your spouse’s talcum powder, but make sure that it is 100% pure talcum powder. Do not use baby powder or ladies’ dusting powder, or any powder that contains fragrances, cornstarch, zinc oxide, or other additives! These products are oiled to protect delicate skin, and oil eats rubber. Pen sacs are rubber… If there’s no plain talcum powder in the house, go buy a can. (I should point out that pure talcum powder is very hard to find these days; your best bet may be from a billiards supplier.) If you absolutely cannot find talcum powder, you can substitute powdered graphite. This stuff is sold by hardware stores and locksmiths for lubricating locks and other mechanisms that are exposed to cold and wet. It’s messy, but it does work.

The last pen-geek item you’ll need is section pliers. Many pens — most, really — don’t call for the big guns, so you may not need section pliers immediately. When the time comes, you can buy very good ones from Fountain Pen Hospital (shown here) or from Father Terry Koch.

Note that the Fountain Pen Hospital pliers shown here are actually intended by their manufacturer, K–D Tools, for use on automobile spark plug wires. You may be able to find them for a lower price at an auto parts store.

If you have a bench grinder, you can make your own section pliers out of garden-variety slip-joint pliers from a hardware store and some rubber fuel-line tubing from an auto parts store. If you go this route, you’ll need two pieces of tubing, each about an inch long, of a size to slip securely over one jaw of the pliers. Grind the teeth of the concave serrated part of the jaws, leaving a smooth curve, and slip one rubber onto each jaw. Position them so that they cover the part of the jaws that you ground smooth; that’s the area in which you’ll grip a section.

This is exactly the way Father Terry makes his section pliers, and to be quite frank, I bought a pair from him rather than expend the effort to make them.

Okay, you have the tools (with one possible afterthought, of which more below). Sit yourself down at a well-lighted table or desk, and we’re off.

Disassembly, Cleaning, and Sac Removal

The first job is to get the old sac out. This means taking the pen apart. Most pens have a section that is a slip friction fit (just pushed into the barrel), but some (notably button fillers, Touchdowns, and Snorkels) have a threaded section that screws out. Virtually all lever fillers, except a few early Sheaffers, are a slip fit. For simplicity, I’m going to describe only the typical slip-fit lever-filler in this article. (If you decide you like this kind of work, get a copy of “Da Book,” Frank Dubiel’s indispensable guide to fountain pen repair, and let Frank show you how to handle the more esoteric pens.)

First, try using your fingers to rock the section gently back and forth sideways, pulling as you rock, to break it loose. Don’t rock too far or you risk cracking the barrel!

If it refuses to budge, it’s probably shellacked in place. (Sheaffer shellacked violated sections but not hard rubber ones, for example.) You can resort to section pliers. Grasp the barrel firmly in your closed fist. (You can enhance your grip by using a rubber kitchen jar-lid gripper.) On the other hand, apply the section pliers to the section, and repeat the rocking/pulling action, twisting a little as if to unscrew the section. If it’s a slip-fitter, it’ll come loose unless it’s been shellacked in place, or possibly even glued (as on Waterman’s Taperite from the 1940s). In that case, you’re better off leaving it to a professional. Yes, I know, you just blew the price of a pen on tools. Use them on the next pen.

With the section loosened, you should be able to work it gently out of the barrel. Use your fingernails or a sharp kitchen knife to scrape all remaining fragments of the sac from the end of the section (the nipple). You need to get the nipple as clean as possible so the new sac will adhere properly. You can use your knife to scrape off the shellac that is probably there, and you can use rubbing alcohol as a solvent for this operation. But don’t use alcohol on a violated section; the plastic used for isolated sections is likely to be soluble in alcohol!

This is your opportunity to do your pen a favor by giving it a thorough cleaning. Drop the section assembly into a bath of diluted clear household ammonia for five or ten minutes. Make your solution by mixing 1 tablespoon (15 cc) of ammonia with 2/3 cup (160 cc) of water. After soaking the parts, scrupulously clean off any ink residue and the cleaning solution. This means flushing water through the system, which you can do by using an ear syringe to force water through the section from the sac end. (If you don’t have an ear syringe, you can use your mouth for this job.) When the assembly is clean, dry it thoroughly; blow some air through to dry the inside.

Clean the cap the same way, paying particular attention to getting the ink out from inside the cap. One way to do this is to use a paper napkin. Twist one corner of the napkin into a long thin spear, and insert it into the cap with a screwing motion. Turn in the direction that will keep the twist tight. Drive the paper as far down as you can get it. Repeat as necessary.

Now, if the sac didn’t come out in one piece, extract its remains from the barrel. Long thin alligator pliers, such as you can get from Wood Bin Ltd, Fountain Pen Hospital, or Widget Supply, can be helpful here but isn’t a necessity. If the sac is ossified, you can probably just dump out the chips. Occasionally you’ll run into a sac that has managed to glue itself, whole or in pieces, to the inside of the barrel. This can get ugly. I use various “afterthought” tools such as dental picks and scalers to chisel pieces of sac away from barrel walls. You can get dental picks from Wood Bin Ltd or Widget Supply. I find scalers very useful, and I get them from KV Vet Supply. Take your time; as with the nipple, you want to get the barrel clean. Be careful not to damage the filler assembly.

If the old sac died and dumped ink all over the inside of the pen, clean the barrel, too. You may also find that using your soaking solution on a barrel will make it easier to extract glued-in bits of the sac. Get the barrel absolutely dry afterward; any moisture left inside can corrode the parts of the filling assembly.

Sac Selection and Installation

With everything clean, you’re finally ready to install a new sac. If you don’t know the right size, try different sizes (you bought the assortment, right?) until you find a sac that just slips snugly into the barrel with the filler assembly in place. Then choose a sac two numbers smaller; if a No. 18 fits snugly, use a No. 16. You need to leave air space between the sac and the barrel to keep the pen from transferring your body heat into the sac when the pen is in your pocket. If the sac gets warm, the air in it expands, and it can force ink out through the feed. This makes the inside of the cap very messy, which is why you just cleaned it. No matter what sac size you end up with, it needs to be a stretch fit over the nipple. If you’ve chosen too small a sac, you may have to go up one size. You can try stretching the end of the sac over the nipple to verify that it’ll go.

The sac needs to be the right length. Most sacs are “straight” sacs; that is, the diameter of the sac is the same along its entire length. Sacs are made much too long; you will need to cut your new sac to the right length. To find how long it should be, slide it into the barrel, closed-end first until it hits bottom. Slide it back out about 1/8” (3 mm) so that it won’t butt against the end of the space into which it fits. Clamp it with your thumbnail right where it enters the barrel, and pull it out.

Still clamping it, hold it up to the section, lining your thumbnail up with the step on the section that seats against the end of the barrel. Now mark the point on the sac that corresponds to the step between the nipple and the part of the section that fits into the barrel. This distance will be between 1/4” (6 mm) and 1/2” (13 mm). In the illustration here, you can see a bright line where light is reflecting off the step between the nipple and the rest of the section.

Cut the sac at this point, being careful to cut straight across.

If your pen requires a necked sac (with the open end smaller than the diameter of the rest of the sac, like the neck of a bottle), you must rely on the information in the Pen Sac catalog or else measure the space into which the sac fits and then choose a sac of the proper length. You don’t cut necked sacs; they have to fit right. This may mean that you can’t order the exact sac you need until you’ve taken the pen apart.

With the sac ready to install, apply a small amount of sac cement (shellac) around the outside of the nipple. Be careful not to let the cement get into the inside; it’ll clog the feed — possibly permanently! Spread the open end of the sac, stretch it over the nipple, and adjust it so that it’s pushed all the way down and is seated against the step. If you find that you’re a little clumsy and have trouble fitting the sac in place, you can buy a sac spreader. Pandemonium offers these little gems for $5.00. I recommend that you buy yours yesterday, as today — with wet cement drying on your pen — isn’t the best time to go shopping. The sac should stand straight up, in line with the section, and the stretched part should be symmetrical on all sides. (The sac shouldn’t be pulled over toward one side of the nipple.) If you like, you can run a very small bead of cement around for an improved seal right where the sac butts against the step.

Once the sac is installed properly, the assembly is down. Go away for half an hour to let the cement dry. It doesn’t necessarily take half an hour, but if you adhere to a firm half-hour waiting period, you’ll never proceed too soon. Getting itchy and proceeding too soon means having a still-wet sac come off in your hands or leak in the pen or — worst of all — glue itself inside the barrel.

Now cover the new sac with a thin coat of talcum powder (or graphite). This will make it slide into the barrel more easily, and the filler will also work a little more smoothly. Reinstall the section into the barrel, aligning the lever with the nib as you go. (Some pens, mostly English brands such as Conway Stewart, usually have their levers aligned on the underside, 180° away from the nib surface.) There’s no need to cement a hard rubber or ordinary plastic section in place unless it’s close to falling out, but Sheaffer has always recommended that violated sections be shellacked in. If your section is so loose that it really does fall out, try shimming it with a bit of paper.

Et le voilà! You’ve just accomplished a task that used to require the services of a highly paid professional. You’re on the road to restoring your way to a better pen collection. Fill your revitalized pen and enjoy the ride!