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Pencil grades vary "depending upon the manufacturer, when the pencils are made, and the source of graphite and clay. One
-
This is not related to the Brinell scale hardness unit HB.
-
The Engines of Our Ingenuity
http://www.uh.edu/engines/epi339.htm -
This testing method is approved by the ISO as standard ISO 15184:1998 Paints and varnishes – Determination of film hardn
https://www.iso.org/standard/55329.html?browse=tc -
75% of the 2.8 billion pencils made in the US are painted yellow (Steve Ritter "Pencils & Pencil Lead", Chemical & Engin
http://pubs.acs.org/cen/whatstuff/stuff/7942sci4.html -
Eagle Pencil Company applied for the trademark Mirado in 1947 (US Trademark 71515261). It is common belief that this was
-
Mikado/Mirado pencils were originally made by Eagle Pencil Company – today Berol – but can also be found today under the
http://www.brandnamepencils.com/brands/eagle/mikado174.shtml -
Originally made by Eberhard Faber the Mongol trademark is now owned by Sanford Timberlines.blogspot.com Archived 4 March
http://timberlines.blogspot.com/2005/08/mongolized.html -
Oxford English Dictionary
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Notes and Queries
https://books.google.com/books?id=UnpIAQAAMAAJ&pg=PA419 -
Chemistry
https://archive.org/details/chemistrythediti00zumd -
"Old Cumbria Gazetteer, black lead mine, Seathwaite"
http://www.geog.port.ac.uk/webmap/thelakes/html/lgaz/lk00976.htm -
A Pictorial Guide to the Lakeland Fells, Western Fells
-
"Graphite from the Plumbago Mine, Borrowdale, England"
http://www.phy.mtu.edu/~jaszczak/borrowdale.html -
Petroski, 1990, pp. 168, 358
-
"Lakeland's Mining Heritage"
http://www.cumbria-industries.org.uk/wad.htm -
"Definition of Plumbago"
http://www.answers.com/topic/plumbago -
"Definition of Plumbago"
http://www.thefreedictionary.com/plumbago -
The big book of questions and answers, Publications International LTD, (1989), p.189, ISBN 0-88176-670-4.
-
BBC Science Focus Magazine
https://www.sciencefocus.com/science/have-pencils-ever-contained-lead/ -
The Washington Post
https://www.washingtonpost.com/lifestyle/kidspost/ever-wondered-about-the-lead-in-pencils/2014/11/26/f8b5869c-548a-11e4-809b-8cc0a295c773_story.html -
www.nlm.nih.gov
https://www.medlineplus.gov/ency/article/002817.htm -
umeshmadan.wordpress.com
https://umeshmadan.wordpress.com/tag/graphite-pencils/ -
www.sciencekids.co.nz
http://www.sciencekids.co.nz/sciencefacts/metals/lead.html -
"Keswick Pencil Museum"
http://www.pencilmuseum.co.uk/ -
Online Etymology Dictionary
http://www.etymonline.com/index.php?term=pencil&allowed_in_frame=0 -
"Who invented the pencil?"
https://web.archive.org/web/20111022205245/http://www.rocketcityspacepioneers.com/space/who-invented-the-pencil -
"Timeline Outline ViewEra: 1500 - 1550"
https://web.archive.org/web/20101231171848/http://www.historyofscience.com/G2I/timeline/index.php?era=1500 -
www.fact-index.com
http://www.fact-index.com/p/pe/pencil.html -
Borrowdale Points
https://borrowdalepoints.wordpress.com/2015/02/10/pencils/ -
www.gyaat.com
http://www.gyaat.com/post_view.php?id=16 -
"History of Koh-i-noor Hardmuth company"
http://www.koh-i-noor.cz/en/history -
Bessemer, Henry (1905) Sir Henry Bessemer, F.R.S: An Autobiography, London, Offices of "Engineering," Chapter 3.
https://archive.org/details/sirhenrybessemer00bessuoft -
"Famous Pencil Users - Pencils.com"
http://pencils.com/famous-pencil-users/ -
"Acton Conservation Lands, Pencil Factory"
https://trails.actonma.gov/pencil-factory/ -
"Joseph Dixon 1799–1869"
https://web.archive.org/web/20071013191609/http://dixonusa.com/index.cfm/fuseaction%3Dhistory.dixon -
"Tantiusques Graphite Mine"
http://www.thetrustees.org/pages/368_tantiusques.cfm -
The Pencil: A History of Design and Circumstance
-
The Point of it All – History of the Pencil
https://web.archive.org/web/20090617220924/http://www.readersdigest.com.au/content/printContent.do?contentId=109024 -
Chicago Tribune
https://www.chicagotribune.com/1993/09/01/in-world-of-politically-right-pencils-can-be-wrong-stuff/ -
"Forest Management Public Summary for: PT Xylo Indah Pratama"
https://web.archive.org/web/20091229141343/http://www.rainforest-alliance.org/forestry/documents/pt-xylo.pdf -
"Fantasia – The Quality Pencil Company – About Us"
http://www.fantasiapencil.com/aboutus.html -
"US Patent 19783 Combination of Lead-Pencil and Eraser"
https://web.archive.org/web/20170502041232/http://patft.uspto.gov/netacgi/nph-Parser?patentnumber=19783 -
Petroski 1990, p. 171
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"Reckendorfer v. Faber 92 U.S. 347 (1875)"
http://supreme.justia.com/us/92/347/case.html -
"Vintage Pen Blog"
https://parkerpens.net/liquidlead.html -
Categories of Wax-Based Drawing Media, palimpsest.stanford.edu
https://web.archive.org/web/20080609001054/http://palimpsest.stanford.edu/waac/wn/wn19/wn19-3/wn19-308.html -
"Carpenter's Pencils"
http://www.pencilpages.com/articles/carpentr.htm -
"History Pencils & Historic Packaging". Faber Castell Australia
https://web.archive.org/web/20080430183938/http://www.faber-castell.com.au/docs/default-news.asp?id=19463&domid=1010&sp=E&addlastid=&m1=14248&m2=16959&m3=19364&m4=19463 -
"Oldest Known Pencil in Existence"
http://www.pencilpages.com/gallery/oldest.htm -
"L. 6 febbraio 1948, n. 29"
https://web.archive.org/web/20121009001506/http://www.senato.it/istituzione/108452/152259/genpagspalla.htm -
"Gel Eyeliner Pencil by ULTA"
http://www.ulta.com/gel-eyeliner-pencil?productId=xlsImpprod4370701 -
"Art Supplies"
https://archive.today/20130128105255/http://www.mccannas.com/sketch/supply.htm -
"Sketch to Paint in Photoshop"
http://www.digitalartsonline.co.uk/tutorials/index.cfm?FeatureID=1625 -
"Tools of the Trade Papers Pencils and Erases"
https://web.archive.org/web/20070708213710/http://smacktalk.smackjeeves.com/03-paperpencilserasers -
"Sanford Col-Erase Copy Not Pencils-You Can't Copy This Baby!"
https://web.archive.org/web/20080524004821/http://www.epinions.com/review/Sanford_Col_erase_Copy_not_colored_pencil_20028_blue/content_285308063364 -
"Paper and Pencil Blog 'Reporter Pencils'"
https://web.archive.org/web/20140728175447/http://www.penciltalk.org/2006/06/reporter-pencils -
World's largest pencil Archived 29 December 2008 at the Wayback Machine. The Pencil Pages.
http://www.pencilpages.com/gallery/largest.htm -
World's largest pencil unveiled in New York Archived 17 May 2017 at the Wayback Machine. Sri Chinmoy News.
http://www.srichinmoybio.co.uk/news/ashrita-furman/worlds-largest-pencil-unveiled-in-new-york/ -
World's largest pencil Archived 5 January 2009 at the Wayback Machine (video). Metacafe.com.
http://www.metacafe.com/watch/835380/worlds_largest_pencil/ -
Grossman, Harold. US Patent 3,360,489 Archived 28 July 2017 at the Wayback Machine, issued 26 December 1967
http://patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/3360489 -
The Epcon Plastic Pencil Archived 8 July 2011 at the Wayback Machine, adlittlechronicles.blogspot.com, for information a
http://adlittlechronicles.blogspot.com/2008/07/epcon-plastic-pencil.html -
"P&P Office Waste Processor"
https://web.archive.org/web/20140113141724/http://dynamicinventions.com/pp-office-waste-processor/ -
Life
https://books.google.com/books?id=_1QEAAAAMBAJ&q=life+Pencils%2C+paint+and+pottery+can+give+you+lead+poisoning&pg=PA46 -
"The HB Graphite Grading Scale"
http://www.pencils.com/hb-graphite-grading-scale -
Petroski 1990, "Appendix A
-
"Staedtler Pencil, video"
https://web.archive.org/web/20130121070208/http://www.staedtler.com/upload/graphite_video_eng_16461.mpg -
Petroski 1990
-
"Derwent Manufacturing Process"
https://web.archive.org/web/20130517110307/http://www.pencils.co.uk/heritage.aspx?id=6&sid=1 -
"Graphite Grading Scales Explained"
https://pencils.com/hb-graphite-grading-scale -
えんぴつのナゾを解く Archived 3 October 2015 at the Wayback Machine. Mitsubishi Pencil Company (in Japanese).
http://www.mpuni.co.jp/museum/qa/mistery05.html -
"KOH-I-NOOR HARDTMUTH HISTORY"
https://www.koh-i-noor.cz/en/history -
"Castell 9000 brochure"
https://www.faber-castell.com/-/media/Faber-Castell-new/PDF/en/Castell-9000-en.ashx -
"Graphite Grading Scales Explained" Archived 6 February 2017 at the Wayback Machine. Pencils.com.
https://pencils.com/hb-graphite-grading-scale/ -
Memoirs, Including Original Journals, Letters, Papers, and Antiquarian Tracts, of the Late Charles Alfred Stothard, F.S.A.
https://books.google.com/books?id=aw1fAAAAcAAJ&dq=%22marked+H.+B.%22&pg=PA154 -
Petroski 1990, p. 157
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"Interesting information about the company"
http://www.koh-i-noor.cz/en/interesting-information-about-the-company -
The New Yorker
https://thescene.com/watch/thenewyorker/comma-queen-on-impact -
Koh-i-noor Catalog: Graphite Pencis, koh-i-noor.cz
https://web.archive.org/web/20071029104124/http://www.koh-i-noor.cz/main/main.php?pageid=3211&lang=4&=&filter=&cat=24&position=30 -
コード表, mpuni.co.jp (Japanese)
https://web.archive.org/web/20081106131833/http://www.mpuni.co.jp/product/category/pencil/uni/spec.html -
"Derwent Graphic"
https://web.archive.org/web/20090619105057/http://www.pencils.co.uk/products/derwent.aspx?sid=3&p=1 -
Staedtler Mars Lumograph Pencils Staedtler.com. Retrieved 25 August 2019.
https://www.staedtler.com/uk/en/products/pencils-and-accessories/graphite-pencils/mars-lumograph-100-drawing-pencil-100-g24/ -
www.pencilpages.com
http://www.pencilpages.com/articles/grades.htm -
"The Pencil Grading Scale Explained 2025: A Comprehensive Guide to Graphite Drawing Pencils"
https://cecelyv.com/pencil-grading-scale/ -
Woodwork
http://www.pencilpages.com/articles/simmons.htm -
Petroski 1990, pp. 162–163
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Why the pencil is perfect | Small Thing Big Idea, a TED series
https://www.youtube.com/watch?v=IBf9pXOmpFw -
"Eberhard Faber Pencil Gallery"
http://www.pencilpages.com/gallery/eberhard-faber/mongol.htm -
"Why Are Pencils Yellow?"
https://www.cbsnews.com/news/why-are-pencils-yellow/ -
Khatabook
https://khatabook.com/blog/best-pencil-brands-in-india/
