Washer Clip - patented on September 5, 1916. Allowed pen to be placed deeply in the pocket.
Lucky Curve feed – patented in 1894, the curved feed touches the inside of the barrel and when the pen is inverted
in a pocket, capillary action draws the ink down out of the nib and back into the reservoir.
Button Filler – extends through the end of the barrel and is protected by the blind cap.
When Kenneth Parker joined the family business in 1919, almost all pens were black and sold for about $2.75. About that
time, the idea for a new pen was proposed. It was to be a large pen with a large ink capacity and a large gold nib. It was
to be produced from a vivid red-orange material and sell for $7.00. A seven-dollar price tag was more than twice the generally
accepted price then for pens. George S. Parker approved the start of the "Duofold pen project" and assigned it to his younger
son Kenneth.
The Parker Duofold pen was introduced in 1921 and was formally launched in Chicago in March 1922 with intensive newspaper
ads and color posters.
Parker modified the highly successful Duofold line almost continuously. As a consequence, collectors can establish the
date of their particular Duofold within a year or so:
1921-2 – Senior style (only) with no cap band; made from a heavy style hard rubber (HR).
The barrel imprint was large (sometimes termed "Giant Imprint". Sold for $7.00
1922 – Junior Duofold introduced at $5.00. In addition, a new line called Duofold De Luxe was introduced with a very
wide cap band which completely covered and protected the cap lip.
1923 – a single, slightly raised cap band was fitted to the Senior and Junior Duofolds.
1923 – towards the end of the year, black hard rubber (BHR) Duofolds were introduced in all models in both the regular
and Deluxe lines. Parker rented a factory in Toronto, Canada and in the following year, plants were making Parker products
in numerous plants around the world.
1924 – a lighter style HR was introduced and the barrel imprints were reduced in size. This so-called "medium imprint",
was used until 1926 when plastic models were introduced. Parker established a subsidiary in England in 1924; despite a shaky
start, the UK branch became so successful that it eventually took over the parent company.
1925 – three new pencils were introduced. The Senior model was nicknamed Big Brother and carried the inscription
"Big Bro’ on the barrel.
1926 – pens made from a Dupont plastic material called "Permanite" were introduced in both red and black. The barrel
imprint was redesigned and the cap band made slightly wider and fitted flush with the cap.
The Jade Pens in three sizes and matching pencils were identical to Duofold models but did not carry the Duofold trademark
until mid-1927
1927 – two new colors, lapis lazuli blue and mandarin yellow were introduced. Two further models of Duofold pens
were introduced – Special and Juniorette. The Special has the girth of a Junior but is almost as long as a Senior; the
Juniorette is identical with the Lady model but is fitted with a clip.
1928 – The Company announced the Imperial Duofold, later known as the Duofold De Luxe. The cream and black veined
plastic pen had a three-band cap and the nib was additionally engraved with the word "De Luxe". The guarantee changed from
25 years to "lifetime".
1929 - The Lucky Curve feed was abandoned. The new feed retained the familiar "spear feed" design but the internal end
was flat. The "Lucky Curve" banner was removed from the imprint. The same imprint was used on the so-called "streamlined"
Duofolds which soon followed.
1930 – Two new colors were introduced in 1930, burgundy and black (with two cap rings) and the De Luxe green pearl
and pearl (three cap rings). Quink, a pen cleaning formula ink was brought on the market.
1932 – the final color of the Duofold line, sea-green pearl and black. The pen appears to be of the De Luxe series,
although both two and three cap bands are found. Later in 1932 the three cap rings of the De Luxe Duofold were modified such
that the center band is wider and the two outside bands are narrower.
Parker Vacumatics were introduced in 1932 and largely replaced the Duofold.
