An Overview of Leather Paring Knives, Tools and Machines

Many bookbinders, when getting into leather binding, are surprised by the wide variety of leather paring knives and machines. In bookbinding terminology there are four basic styles of knives and they are named for the nations that generally use them: English, French, German and Swiss. Other leather crafts use different terminologies.

In addition to paring knives, many binders use paring tools and machines. Most commonly a modified 151 style spokeshave, a double edge razor blade paring machine, or more rarely a razor blade plane. If you have a lot of work, skins can be sent out to be split. A few also thin leather by sanding or grinding. Below are my observations on the advantages and disadvantages of all of these.

 

1. English Style Knives (a straight blade, usually around 45 degrees relative to the length)

In North America, most binders use an English Style knife for edge paring, followed by a spokeshave for making a long, gradual bevels. This type of beveling is used for English style fine bindings and rebacking. The knife making firm G. Barnsley made the most common knives used by English bookbinders in the 20th century.

ADVANAGES

• Comparatively easy to sharpen
• Easiest to learn to use
• Best for edge paring
• Modern tip style paring technique is easier to learn and control than a traditional heel technique

DISADVANTAGES

• Can only be used for edge paring
• You will need a different style knife, a spokeshave, or a razor blade paring machine to thin larger areas

 

2. French or Swiss Style Knives (usually a slightly rounded blade, Swiss knives do not have a handle)

French style knives are very popular with fine binders, many of whom were French trained. One defining stylistic feature is a center mounted wood handle, however. The handle on the French knives has always puzzled me, since you tend to hold it more on the blade and rest your palm on the handle. The handle protrudes onto the leather, limiting the angle the knife can be held. To get lower paring angle, I was the first to introduce the top mounted wood handle.

ADVANTAGES

• One knife can do it all, though some binders use this in conjunction with an English style knife
• Can be used with a scraping motion for thinning anywhere in a skin, useful for headcap or spine areas
• Round blades seem to stay sharp longer, since there is at least some area that is still sharp enough to get a “bite” into the leather

DISADVANTAGES

• Much more difficult to resharpen
• More difficult to learn to use
• More difficult to control
• Scraping with a knife is more dangerous than spokeshaving or using a razor blade paring machine

 

3. German Style Knives

I’ve only used these a couple of times, so don’t really have an opinion. I did have a German trained student who used it expertly.  The one I have is slightly flexible. In  Zaehnsdorf’s 1890 The Art of Bookbinding, the German paring knife looks like a regular chef’s knife. Even the modern versions have a wedge shaped taper, so that the back is fairly thick and the opposite edge is sharp. Did the modern German style knife morph from a regular chef’s knife?

 

4. Modified 151 Spokeshave

A modified 151 style spokeshave is a powerful and effective tool for making long, gradual bevels in leather; ideal for rebacking or an English style full leather binding. It can also be used to bevel binders board. It is a lot of fun to use. These were originally intended for woodworkers, and I think binders started to modify these for leather starting in the 1920’s. Here is some of my research, and a tentative type study of 151 style spokeshaves.

ADVANTAGES

• Much faster than a French knife for reducing leather thickness over a large area
• Less chance of tearing through leather, especially with a shaving collector
• A must for calf, which tears or gets marked in a razor blade paring machine

DISADVANTAGES

• Difficult to modify a regular 151 style spokeshave
• There is a bit of a learning curve to learn to use them
• The leather must be clamped to the stone or glass, or the leather can be traditionally held with your stomach
• Can’t be used with leather smaller than 6 inches or so in one direction, to allow for room for clamps and motion of the spokeshave

 

5. Razor Blade Leather Paring Machines: Scharffix, Bockman Paring Machine, and the forthcoming Felsted Skiver

Razor blade paring machines, including the Scharffix, Brockman and the new “Felsted Skiver” all use a very similar arrangement: a double edge razor blade suspended above an anvil or roller. These are very useful for thinning small or large areas flat. Razor blade machines excel at paring leather very thin. Common bookbinding applications include millimeter bindings, spines and corners for half bindings, and most commonly leather labels. A spokeshave is sometimes used to clean up ridges created from overlapping cuts on larger pieces.

My favorite paring machine is the original style Brockman, which is not available new anymore.  One advantage of his design is a curved bed for for the razor blade, which gives it significant rigidity and positions it to cut into the the leather straight on, rather than at an angle. Older hand held double edge razor blade handles also bend the blade like this. Brockman told me he made the first 100 of them himself, which are painted blue, and the later black ones were manufactured for him. A third green cast version was briefly produced in the 2000s (?), which looked very nice, but I haven’t tried it.

There are rigidity problems with many Scharffix machines, so make sure to test them out before purchase.

I’m looking forward to trying out the newest machine, the Felsted Skiver. Malcolm Raggett designed and is selling these. He has tested a variety of commercially available double edge razor blades, which is very useful research, and confirmed the Feather as one of the best blades.. But as I mentioned, I haven’t tried them out yet.

ADVANTAGES

• Short learning curve
• The best for paring very thin, flat areas of leather, like labels or half-leather bindings

DISADVANTAGES

• Difficult to create bevels (at least for me)
• Almost impossible to use on vegetable tanned calfskin
• Blades wear out quickly and need to be replaced
• Some of the machines can be tempermental
• Changing the blade can alter the cutting depth

 

6. Razor Blade Planes

I wrote a brief history of them, then added some tips on their use, and later recorded my failed attempt to make a better version.  I ended up tearing a lot of leather, and went back to using a 151 modified spokeshave and razor blade paring machine. One skin can be as expensive as any of these tools.

 

7. Sending your Skin to a Specialist

This used to be common for french design binders, who even indicated what thickness the leather should be at various areas, through use of a template.  I’ve heard these specialists are disappearing, though. We do have leather manufactures who will split a skin (or more likely a dozen) down to a certain thickness. This is an excellent option if you are an edition binder. If the skin is thick enough you can get both sides back. The machine that does this is like a toothless horozontal bandsaw. I’ve used Hohenforst Splitting Company and they did an excellent job on a difficult leather: undyed and unfinished calfskin.

 

8. Sanding or Grinding

I wouldn’t recommend either of these methods unless there are extraordinary circumstances. Not only do these methods produce a lot of hazardous dust, they are very slow and, at least in my experience, grinding is very uncontrollable. I have done this if the leather is exceptionally weak, or need to level chatter that has resulted from an improperly tuned spokeshave. In this case choose a very coarse sandpaper, around 80 US grit. Sanding an entire piece of leather for rebacking or covering is very tedious.

Conclusion

After saying all of this, I think any knife made from good steel, properly hardened, that is hand sharpened, can work. I did some testing of tool steels and a summary is posted here. But I do think it is easiest to start with a hand sharpened knife, like the ones I sell in my store, in order to feel what sharp is, then learn to maintain this by stropping and eventually by resharpening.Happy paring!