Category Archives: book conservation

An Ugly Hunk

Image: Ref 1996.8.1

Any guesses what is pictured in the above image?

I’m really happy museums are collecting this kind of thing.

It is from the Maritime Heritage East, and it is a hunk of beeswax that sailors waxed their whipping cord with, much like traditional bookbinders do with sewing thread. Looking at this, I can see how someone pulled the thread through it, likely holding it in one hand between their thumb and forefinger and rotating it 90 degrees occasionally to prevent the thread from cutting through. In fact, the museum notes that Harold Scot, an orphan sailer, received this wax in 1933 when he was 16, and used it for the next 66 years. It is unusual to have this type of provenance concerning tools and craft materials.

So what? Why does this ugly hunk of beeswax matter? Because here we have a physical record of technique, seemingly frozen in time. We can interpret the technique from this object, and it is an interesting object because it is a material that acts like a tool. The thread is shaped the wax, somewhat like a potter’s rib shapes clay. It is difficult to know, from this isolated example, if this was a common technique or waxing thread, a local custom, or possibly novel.  It would be interesting to compare other examples of beeswax, possibly from other trades. Was this hand sized square of wax a common size?

We do know that using beeswax to prevent kinking and reducing abrasion of sewing thread was common in many trades, including bookbinding. Yet materials like this are not commonly passed on when a bindery is sold. The use of beeswax seems to be waning, because of concerns about acidity and the fact it is not really necessary if the needle is the right size, and the thread properly relaxed. In fact, the sewing thread of most early bindings I’ve examined does not seem to be waxed.

beeswax in holder

Image: <;

A 20th century “innovation” in beeswax is the plastic holder pictured above, which is marketed to bookbinders and other sewing related crafts and even sold at Walmart. I suspect that one motive was to sell more tiny disks of beeswax, and the holder encourages waste because only part of the wax can be used. To be fair, the holder does keep the beeswax and the workers hands clean. But unless you are very careful, it is easy to abrade the thread on the sharp plastic edges, in contrast to the advertising claim that this device “strengthens” the thread. What does the holder, with its regulated placement of the thread imply about the marketing and deskilling technique in modern craft? Is the holder akin to training wheels?

Since the history of craft technique is generally unwritten, it is the responsibility of craft practitioners and conservators to interpret—or at least preserve and draw awareness—to these physical traces of past technique.


Christmas Gift Ideas for Bookbinders, 2014

Below are four inexpensive and useful items that I imagine any bookbinder or book conservator would love to get.

If, perchance, you are thinking of getting me a gift, I really, really, want the new Panasonic Lumix DMC-GM5.  Black, please. Thanks in advance!

Disposable Scalpels

1. The Southmedic disposable plastic handled scalpel. The blades are not removable, which makes them feel quite solid. The blade cover easily slides back and forth, protecting them while traveling.  I stop mine (with a small horsebutt strop) to keep it sharp and they last for quite some time. They come in two of my two favorite shapes, #11 and #15. There is a useful metric scale at the end of the handle for determining the depth of puncture wounds. Great fun for kids! McMaster-Carr sells them. About $3.



feather blades

2.  Japanese Feather brand double edge razor blades.  Apart from vintage, NOS blades, these are the best I have found for Scharfix and Brockman paring machines.  The Feather company may be familiar to some, since they also make scalpel blades. Hipsters love them for use in vintage double edge razor blade handles. Many vendors on Amazon sell them at various prices, around 30 cents each.



delrin in hand

3. Delrin Folder.  Delrin folders are new, and to my knowledge far I am the only one making them. They combine many advantages of bone and teflon. I know who has them if you are buying a gift, just ask! But get one for yourself as well. These are designed to perform a number of common scoring, folding and smoothing tasks bookbinders need when working with paper, cloth and leather. The big boy pictured above is $65, smaller ones are also available starting at a mere $35.




phd target

4. Small AIC PhD Target.  It is awesome to finally have a small, affordable color bar to use for documentation.  It used to drive me crazy fitting in a larger bar, which would almost be equal to the size of the book in some cases, resulting in the loss of detail, messing up framing, etc.  Robin Meyers Imaging produces and sells them. Excellent! $75



Heat Treated Tonkin Hera


I’ve done some research and ramped up the quality of the bamboo I use to make hera.

First I have decided to use Tonkin, a super strong and resilient bamboo which is used by bamboo fly fishing rod makers. As evident in the image above, it has a preponderance of dark “power fibers”, which give it strength and a pleasing density.  Look at the end of a chopstick for comparison, which is generally pure white weak pith. There are over 1,000 species of bamboo.

I’ve also decided to heat treat the bamboo after initial shaping.  Dr. Wolfram Schott has a fantastic paper, Bamboo in the Laboratory, if you are interested in more details. His Bamboo under the Microscope is also highly recommended. Both breaking strength and modulus of elasticity increases according to his research and tradition in rod making. I’m not totally convinced it makes a difference for such small tools, but it certainly doesn’t seem to hurt. And the stove adds a comfortable warmth on these increasingly cold fall days!

Heat treated Tonkin Hera for sale, $25


New Hera

Dividers; or, What Problem?

stevens dividers

Some of my dividers.  

Sara Bryant of Big Jump Press wrote a breathlessly enthusiastic ode to dividers last month on her blog. Apart from extolling the virtues of comparison measurement, she wondered aloud if she perhaps was becoming a hoarder beause she has six pairs, and if it might be a problem.

My dear Sara, rest assured, you do not have a problem.

stevens divider

My favorite dividers, a 19th century Stevens & Co. Note the unusual, and extremely elegant position of the adjustment screw above the pivot point.

Paring on Glass

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Charles Tomas Jacobi The Printers’ Handbook of Trade Recipes, Hints & Suggestions  (London: Chiswick Press, 1891), 265.

Yes, yes, and yes. Note there is no mention of a litho stone. 18th century paring surfaces seem to generally be marble, I suspect the only reason litho stones became popular was that they were a cheap plentiful source of a flat surface in the late 19th. Save the litho stones for the printers or your beautiful bookbinding photography.

Tips On Making a Delrin Folder

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In this scene from Stanley Kubrick’s classic 2001: A Space Odyssey, the ape is dissatisfied with the properties of natural bone. I suspect he wants a Delrin club. Here is a great explication of the film.

Seriously, animals do tinker with their tools, and so can you. It is an intensely satisfying experience. It gives you a lot of freedom and confidence in designing, executing and using a specific tool for your individual needs. It is interesting to see how tools you have made wear, perform and even may fail in use.

While bone can only be harvested from dead animals, Delrin is mass produced and easily obtained from many suppliers. It is a very hard plastic, originally invented by Du Pont in 1960 to bridge the gap between plastics and metal. There is a dust hazard, as there is for wood, so you should review the MSDS and wear PPE.


1. PLANNING.  It is a good idea to think and experiment a bit with what you like, or don’t like in the folders you are currently using. Monica Holtsclaw has a great introduction to various shaped folders for various purposes. How do you hold it? Do you use both ends? Do you like sharp or rounded angles? Is it for scoring, folding, and/or burnishing? What different operations do you intend to use it for? Making a crude mockup out of binders board glued together for thickness can give a much better sense of what the actual product might feel like and fit your hand. Alternatively, full size scale diagrams are also quite informative. Here is my idea of the ideal shape.

2. ORDERING MATERIALS AND TOOLS.  Obviously, it is easiest to order the Delrin closest to the size you need for the final shape. Mc-Master Carr carries an extensive variety of sizes, but consider yourself warned; their website is more addictive than cheap baggies of high potency heroin. As far as tools, I recommend a 24 tpi hacksaw if you don’t have a bandsaw, a small vice, an 8-inch coarse bastard file with handle, a woodworkers card scraper, a burnisher for putting and keeping the hook on the scraper, and an assortment of 3M sanding sponges for final polishing.

3. ROUGHING OUT. Delrin is easily marked with a soft pencil. Cut it out using a bandsaw or 24tpi hacksaw. The more care you take in cutting evenly and accurately the less time you will need to spend cleaning it up later. A bandsaw makes the roughing out much quicker and I find it easier to get a more accurate cut. Indeed, a bandsaw makes everything — even mistakes and accidents — much quicker.

4. SHAPING. Initial shaping is most easily accomplished by filing. I prefer an 8 inch Nicholson Magicut.  It works well on wood, plastics and laminates. I find the older ones made in USA better made the the newer imported ones. Alternatively any coarse bastard file can be used. Always mount a handle, otherwise the tang can cause serious injury. Grinding or sandpaper tends to produce very deep scratches that are difficult to remove, and I would be nervous about the amount of dust generated. I have experimented a bit with a plane and spokeshave, which kind of worked, but resulted in lots of chatter, unpredictable chipping, and a difficult to clean up surface. It can also be shaped with metal working tools such as a milling machine. And who isn’t looking for a good excuse to buy a table top milling machine?

5. FINISHING.  I find hand scraping (with a woodworkers card scraper) produces the most successful surface finish after filing. You will need to learn how to sharpen it and turn the burr. Scraping is also virtually dust free, since the shavings are a couple of a thousandths of an inch thick and tend not to become airborne. There is some other good advice on finishing Delrin from this thread in the Practical Machinist. In general, the finish of Delrin reflects the tool used. Delrin is very clean and nonabrasive, consequently your tools stay sharp for a very long time. It is a great way to learn about scraping, since it doesn’t have a grain direction to worry about like wood.  A final polish with a progression of 3m sanding sponges, gives it a pretty good finish. The higher the polish the easier it is to clean, and I find the more bone-like it feels.

Delrin is not yet easily available to use in a 3d printer, though I suspect it will be in a couple of months/ years. This could be very cool: one of the most useful and intimate bookbinding tools to be customized and printed on demand. For now, stock reduction is not all that difficult. I’d be interested to hear if anyone has experimented with other plastics for folders.

If you have a bit of experience shaping metal or wood, Delrin is not that different. It is a slightly challenging, but rewarding material to work with hand tools. If making tools is not your cup of tea, you can always purchase a ready to use folder from me, and use this info to tweak it a bit to suit your personal preferences.

I’ve planned a workshop on making Delrin folders. I’ll give it a test drive in a couple of weeks on full time North Bennet Street School bookbinding students. Contact me if you are interested in hosting something similar at your location.


delrin in progress

The Delrin Folder

Mr. McGuire: I just want to say one word to you. Just one word.

Benjamin: Yes, sir.

Mr. McGuire: Are you listening?

Benjamin: Yes, I am.

Mr. McGuire: Plastics.

Benjamin: Exactly how do you mean?

-The Graduate (1967)


Bookbinders have used a variety of materials for folders. Wood, bone, and ivory are common traditional materials. The Excelsior metal folder, made from aluminum bronze, is an oddball patent from 1889. Nylon, bakelite, carbon fiber, Teflon and sometimes even steel have been used more recently.   Today, most bookbinders and book conservators use bone and Teflon. Each material has its advantages.

Earlier this summer, senior rare book conservator at Harvard Library, Alan Puglia, showed me a small spatula for pigment consolidation, which he made out of Delrin. Delrin is a plastic which was invented by Du Pont in 1960. Alan mentioned several advantages of this material, including its low coefficient of friction and rigidity. The material seemed ideal not only for spatulas, but folders.

After making a folder and test driving it for a while, I became a devotee. It is a great material for a folder ( apologies Jim Croft ) combining advantages of both bone and teflon, while not feeling plasticky and soft like Teflon. It can be shaped with hand tools. It is food compliant and impact resistant.  It is used for the stock of the M16 rifle. Du Pont’s informational Delrin booklet.

Delrin is much stiffer than Teflon, and twice as hard, yet has about the same coefficient of friction.  The hardness of Delrin is 120 on the Rockwell R scale, Teflon is 58.  Delrin has a dynamic coefficient of friction of .35, and Teflon about  .2.  More technical specifications of Delrin and Teflon. I had a lot of trouble finding technical specifications on dried bone, possibly because they can vary so much, but this article, “The Mechanical Properties of Bone” , is somewhat useful.  There is a dust hazard in working Delrin, MSDS here. Because of its slipperiness, all adhesives I’ve tried are easily wiped off, even if dried. Delrin is not quite as dense as Teflon. Teflon is 2.2 grams per cubic centimeter, Delrin 1.41 grams per cubic centimeter. Searching for “Bone Density” leads to entirely different results.

Plastics, unlike natural bone, can be made in almost any shape or size. This gives the maker a wide range of possibilities in designing a folder, since there are essentially no limitations on the shape.  I decided on this shape began by examining how I use folders and the various ways I hold them. I notice I often used a Teflon folder flat, as a burnisher, so needed it to be fairly thick and have smoothly rounded corners. Unlike Teflon, Delrin is that a folder can have large gently rounded, non-marring areas and fairly thin, knife like sharp areas that don’t distort like Teflon.

I am a firm believer in the importance of learning how to make and modify your own tools. Next week I will share some DIY tips for making Delrin folders. I’m almost embarrassed how much I enjoy working it by using hand tools. It has no grain, so can be attacked from any angle, and it is very clean, so tools stay sharp a very long time. Like most plastics, it doesn’t have a “mind” of its own but is consistently compliant with the tools and wishes of the maker. Benjamin?





delrin 2




This folder is carefully designed to accomplish all the general uses a bookbinder or conservator has: scoring, folding, turning-in, applying non-marring local pressure, large scale smoothing. The small rounded tip area is shipped slightly blunt, but it can be sharpened if you prefer. Delrin is hard and stiff like bone, but has a coefficient of friction similar to Teflon. It can hold a much thinner and sharper edge than Teflon. It has a nice, non-plasticy feel. I saw, file, scrape and polish these from a solid block of Delrin.

Delrin Folder:  6.5 x 1 x .375 inch. $65.00