One of the fringe benefits of maintaining an enthusiast website is that I get to meet other enthusiasts. I've been lucky enough to coax some information out of some of them. I try to keep this list reasonably up-to-date and inclusive, but if I've missed anyone, I apologize.

contributor		contribution		contact
Kevin Boyd (USA)		Leadholders.		bisoncat@comcast.net		Collector.
Dan Burkholder (USA)		Information about photographic negative retouching.		danphoto@aol.com		www.danburkholder.com Author of the book nobody should be without: “Making Digital Negatives for Contact Printing.”
Caran d’Ache S.A. (Switzerland)		Images and a chronology of the Fixpencil.		www.carandache.com		Swiss maker of writing instruments: www.carandache.com.
Cheng-Lung Chang (USA?)		Information.		cheng-lung.chang@kodak.com		Collector.
Carla Eloise Chait (USA?)		Poetry.				Writer.
David Cullen (USA)		Numerous excellent leadholders, and information.		iq168@cox.net		Collector.
Glenn Day (USA)		Image of an Alteneder leadholder.				Collector.
Russell Erwin (USA)		Scans of Winsor & Newton leadholder set.				Collector and Artist.
Mark Frankena (USA)		Vintage catalog copies.		frankena.m@ei.com		curator of the fantastic Early Office Museum
Michael Fultz (USA)		Information about Theo. Alteneder & Sons and catalog scan.		fultzpens@aol.com		Dealer in writing instruments.
Andrey Gordenko (Russia)		Many leadholder and catalog scans.				Collector and dealer.
Paul Hunt (United Kingdom)		Many leadholder and catalog scans.				Collector.
isu (Japan)		Several leadholders and pointers of Japanese origin.		leadholderder@yahoo.ne.jp		Collector and author of the blog The Uncomfortable Chair.
Jeremy Ledford (USA)		Some of my coolest thin lead pencils came from Jeremy.		lastwinj@yahoo.com		Collector of thin lead pencils and author of Pencils 11.
Doug Martin (USA)		Examples of woodcased drawing pencils.				Curator of the classic Pencil Pages website.
Allan Macdonald (Australia)		Scans of drafting, specialized, and thin-lead leadholders; and catalog scans.				Collector specializing in drafting pencils and 19th century drafting tools.
Dmytryy Orzhekhovskyy (Ukraine)		Russian and Czech leadholders.		divlor@chat.ru		Creator of the website Ordinary Pencil.
Luca Panaro (Italy)		Several scans of drafting leadholders.				Collector.
Hans Presto (Sweden)		Many pencils and leads and much information.		hans.presto@chello.se		Calligrapher, letterer from Sweden, and creator of the Stalpennorpen nib website.
Gerard & Marijke Prudon (Netherlands)		Dutch leadholders, images, and information on lead pointers.		gprudon@multiweb.nl		Operators of the Netherlands based pencil sharpener club, Puntgaafwhich publishes a catalog of all known pencil sharpeners! (and you thought I was obsessive).
David Riches (United Kingdom)		Leadholder and catalog scans.		drdriches@aol.com		Collector specializing in drafting tools.
Robert Rogers (USA)		Alvin Constructor scans.				Collector.
Dick Rose (USA)		Vintage catalog scans.		rarose@prodigy.net		Dealer in scientific instruments, specializing in slide rules. Operates the site www.rose-vintage-instruments.com.
Les Newcomer (USA)		Information about photographic negative retouching.				Photographer.
Pedro Figueiras Santos (Portugal)		Artwork, leadholders, scans of leadholders, and numerous other things.				Illustrator.
Laurie Schmidtke (USA)		Leadholders loaned to Leadholder to be cataloged and scanned.		herrschmidtke@yahoo.com		Collector.
Ron Westrum (USA)		Loan of vintage catalogs for scans.		ronwestrum@aol.com		Drafting instrument dealer specializing in Swiss tools.
Aram Wool (USA)		Scans of several thin lead drafting leadholders.				Collector.

References/Bibliography

French, Thomas E.
Engineering Drawing
There are numerous editions of this work. I've gathered information from several of them and when I have a chance I'll try to be more specific about which ones.

Hambly, Maya
Drawing Instruments 1580-1980 (Sotheby's), London, 1988
This book has a modicum of information about drafting pencils, but it maily dwells on pretty cased instrument sets, few of which were made to include pencils as such. It's an interesting book regardless and it is profusely illustrated.

Petroski, Henry
The Pencil: A History of Design and Circumstance (Alfred A. Knopf) New York City, 1989
This book is the best single source for pencil history. It really is the only game in town other than manufacturers' catalogs, unless you plan on doing your own historical research into the archives of pencil manufacturers themselves. (But I warn you: the old, esteemed pencil manufacturers have been merged and reorganized so many times in the last 30 years that it is difficult to find someone at say, Sanford Corp., who even knows that they subsumed the Eagle Pencil Co. which was subsumed by Berol which was subsumed by Empire which was subsumed by Sanford.)

All the catalogs in the Vintage Catalog Gallery have been valuable sources of drafting pencil information.