{{Short description|Special pen made with a water-based gel which makes handwriting appear glossy}} {{Infobox product | title = Gel pen | logo = | logo_caption = | logo_alt = | image = Gelpen cylindric tip detail.jpg | image_size = 250 | alt = | caption = Gel pen cylindric tip detail | type = Pen | inventor = Sakura Corp. | inception = {{start date and age|1984}}<ref name=gphist>[https://www.historyofpencils.com/writing-instruments-history/gel-pen-history/ History of Gel Pens] on historyofpencils.com</ref> | manufacturer = Sakura, Pilot, Uni-ball, Paper Mate, Pentel, Zebra | available = Yes | current supplier = | last production = | models = | slogan = | website = | notes = }}

A '''gel pen''' uses ink in which pigment is suspended in a water-based gel.<ref>{{cite journal|url= http://pubs.acs.org/subscribe/archive/ci/31/i09/html/09lw.html |title=The Last Word: Just for the gel of it|date=September 2001|volume= 31|issue= 9|page= IBC|first=Debra A. |last=Schwartz|journal=Chemical Innovation}}</ref> Because the ink is thick and opaque, it shows up more clearly on slick surfaces than the typical inks used in ballpoint or felt tip pens. Gel pens can be used for many types of writing and illustration.

The general design of a gel pen is similar to that of a regular ink-based pen, with a barrel containing the writing mechanism and a cap, and a reservoir filled with ink. At the end of the ink tube is an ink "follower", made of more viscous gelled material which is usually translucent and follows the water-based ink. The follower mainly prevents leakage and back flow of the ink.

The barrels can be created in many different sizes and designs; some have finger grips of rubber or plastic. The size of the nib or pen tip ranges from {{Convert|0.18|mm|in}} to {{Convert|1.5|mm|in}}.

==History== The first gel pens were produced by Sakura Color Products Corporation of Osaka, Japan.<ref>{{Citation |title=Japan |date=2022-04-14 |url=https://www.cia.gov/the-world-factbook/countries/japan/ |archive-url=https://web.archive.org/web/20220416020210/https://www.cia.gov/the-world-factbook/countries/japan/ |url-status=dead |archive-date=April 16, 2022 |work=The World Fact book |publisher=Central Intelligence Agency |language= en |access-date=2022-04-25}}</ref> The first gel pen to be released commercially was the Ball sign 280<ref>{{cite web |title=Who Invented The Gel Pen |url=https://unsharpen.com/who-invented-the-gel-pen/ |website=Unsharpen.com |access-date=1 September 2020}}</ref> in 1984<ref name=gphist/> which was sold by Sakura Color Products in Japan. Their first product which became available in America in the late 1980s was the Gelly Roll.<ref>{{cite web |title=Gelly Roll History |url=https://www.gellyroll.com/history |publisher=GellyRoller.com |archive-url=https://web.archive.org/web/20200102143340/https://www.gellyroll.com/history |access-date=1 September 2020|archive-date=2020-01-02}}</ref> Following this, Crayola began producing pens with thicker bodies, marketing them to children. The gels of these pens were made up of metallic sparkles and fluorescent colors, popular among artists for their easy control and smooth drawing capability.

Door County Sheriff's Office has advised the public to write checks with gel pens which is harder to remove than a regular ink pen.<ref>{{cite news |title=Consumer First Alert: Use gel pens to write checks | url=https://www.wbay.com/2023/04/30/consumer-first-alert-use-gel-pens-write-checks/ |date=April 30, 2023 |publisher=WBAY}}</ref>

==Gel inks== {{multiple image | header = | align = | direction = | total_width = 400 | perrow = 2/1 | image1 = Pen stroke with gel refill (400X).jpg | caption1 = Pen stroke | image2 = GelPen stub.jpg | caption2 = Writing of a gel pen | footer = }} Compared to other inks, gel ink has higher melting point viscosity, which supports a higher proportion of pigments in the medium. The pigments are typically copper phthalocyanine, carbon black and iron oxides, and the gel is made up of water and biopolymers, such as xanthan gum and tragacanth gum, as well as some types of polyacrylate thickeners. The pigments are opaque, and gel pens are available in several bright and pastel colours, as well as opalescent, metallic, and glittery colours which show up clearly on dark paper. Many gel inks are water resistant, and are not washed away by water once the ink has dried. Fraud resistant gel ink is unaffected by solvents such as acetone, and resists check washing.

Gel ink resists an analytical method commonly used to assess the potential age of ink for forensic purposes. The United States Secret Service has maintained the International Ink Library for many decades.<ref>{{cite news |last1=Long |first1=Colleen |title=Secret Service's ink library helps agents foil kidnappings, counterfeiters |url=https://www.sfgate.com/nation/article/Secret-Service-s-ink-library-helps-agents-foil-14079625.php |access-date=27 March 2024 |publisher=SFGATE |date=8 July 2019}}</ref> Because manufacturers change their ink formulas slightly from year to year, thin-layer chromatography (TLC) can be used on ink from traditional pens to trace the manufacturer and date of manufacture of most inks. The pigments in gel ink do not dissolve, and therefore cannot be analyzed with TLC.<ref>{{cite journal | first1 = Gerald | last1 = LaPorte |date=May 2006 | title = An Evaluation of Matching Unknown Writing Inks with the United States International Ink Library | journal = Journal of Forensic Sciences | volume = 51 | issue = 3 | pages = 689–92 | doi = 10.1111/j.1556-4029.2006.00144.x | pmid = 16696723 | last2 = Arredondo | first2 = MD | last3 = McConnell | first3 = TS | last4 = Stephens | first4 = JC | last5 = Cantu | first5 = AA | last6 = Shaffer | first6 = DK| s2cid = 25811934}}</ref>

==Pen Tips== Gel pen tips are constructed similarly to ballpoint pen tips.<ref name=tinte>[http://www.staedtler.at/upload/TintenStifte_10811.pdf Tintenstifte]{{dead link|archivebot=2018-04-11 18:36:03 InternetArchiveBot |date=April 2018|url=http://www.staedtler.at/upload/TintenStifte_10811.pdf}} (PDF; 1,1&nbsp;MB). Staedtler Mars, retrieved 1 March 2012.</ref> The casing is usually made of stainless steel, and the ballpoint is made of carbide or ceramic. The ball diameter is usually between 0.3 and 1.2&nbsp;mm, although East Asian products are available with diameters as small as 0.2&nbsp;mm.<ref>{{citation|author=Gopalpur Nagendrappa |chapter=Abschnitt 10.6.4 |date=2022 |publisher=Notion Press |title=Everyday Chemicals – in and Around Our Homes |isbn=979-8-88833-677-9 |url=https://books.google.com/books?id=i-KgEAAAQBAJ&pg=PT184}}<!-- auto-translated from German by Module:CS1 translator --></ref>

==See also== * List of pen types, brands and companies

==References== {{reflist}}

{{commons category}} {{Pens}}

Category:Pens Category:Products introduced in 1984