New Tool For Sale! The M2 Hybrid Paring Knife

Traditionally, leather paring knives either have round or straight cutting edges.  I discuss the advantages and disadvantages of each in this post. I usually use an English style straight blade, but became tired of the fact it could only be used for edge paring. Partially inspired by the rounded corners of a spokeshave blade, I made a couple of other modifications to a standard M2 English style knife so that it can be used for more than edge paring.

A slightly curved cutting edge on essentially an English style knife allows it to scoop out leather, necessary for the spine area, headcaps, and decorative work. The blade is oriented at a 45 degree angle, like an English knife, so right and left handers need to purchase different knives. The corners of the knife are rounded so that the tip or heal will not cut through the skin while performing this scooping action. The tiny secondary bevel allows quick resharpening.

This knife can be used for all types of paring necessary in bookbinding: edge paring, reducing spine and caps, paring deep into a skin (similar to a spokeshave’s action) and even for overall scraping, if you are into that.

M2 Hybrid Knife. Around 8 – 9 inches long, and 1 inch wide. Since the grind marks on the primary bevel go along the length of the blade, the primary bevel is not apparent when looking at the top of the knife. The exact curve of the cutting edge varies a bit from knife to knife.

A lower angle primary bevel cuts down on the amount of time it takes to resharpen the blade, since there is less metal to remove. The 13 degree cutting edge is only a millimeter or two. The disadvantage is that there is not a large enough bevel that you can feel when you put your knife on the sharpening substrate; you have to trust your hands and the angle you are holding it at. This is quite similar to sharpening a kitchen knife by hand. Another advantage of the small secondary bevel is that it can be stropped back into shape very quickly, again because not much metal has to be removed. This is a perfect blade for sub-micron stropping. M2 steel seems easier to strop than A2, for some reason.

Cross section of primary and secondary bevels.

The slightly curved blade creates more opportunity to find a sharp area as the knife dulls, so it can be used longer. Straight blades, as they become dull, don’t seem to bite the leather enough to get started with a cut. The disadvantage is you can’t just rub it back and forth like a standard straight edged knife when resharpening. Stropping takes a slight twist of the wrist, to keep parts of the cutting edge in contact with the strop throughout the stroke.

The rounded areas allow you to work into a skin, for headcaps and the spine. But the shape also allows you to use it like a standard English style knife for edge paring.

The third change is that the tip and heel of the cutting edge are rounded.  This prevents the knife from cutting through the skin when you are working away from the edge, similar to how a spokeshave blade works. In practice, I don’t miss having a pointed, sharp tip. A rounded tip also makes it less likely to dig into your paring surface.

The M2 Hybrid used like a standard English knife for edge paring.

All of these aspects combine to make a sensitive and versatile knife intended for professionals. An analogy for cyclists might be this is more like a track bike than a road bike. This knife, in addition to edge paring, can do most of what a spokeshave can do, albeit with more “workmanship of risk”. If you want the most versatile knife on the market, look no further.

Close up of a piece of goatskin feather pared,, so that the valleys of the grain are cut through. The middle of the blade was used for this, almost parallel to the edge of the leather..
Progressively paring towards the center. The rounded edges keep the blade from cutting through the leather as it stretches.

M2 Hybrid Paring knife. M2 Steel. The handle is hand carved wood, covered with vegetable tanned goatskin, and ergonomically shaped. The metal is .040″ thick, the handle around 5/8″ at the thickest point. It is about 1 inch wide and around 8-9″ in overall length. The secondary bevel is 13 degrees.  Hand sharpened to .1 micron.

The M2 Hybrid Paring Knife.  $250.00.  Order here.

Small M2 Hybrid knife. The best knife for onlays and intricate leather decorations. Also great for paring paper. M2 Steel. The metal is .025″ thick, about 5/8″ wide and 6-7″ long. Leather covered wood handle. The  secondary bevel is 13 degrees. Hand sharpened to .1 micron.

The Small M2 Hybrid Paring Knife.  $150.00.  Order here.

Small M2 Hybrid knife bottom left, regular size next to it.

Just Looking

Once a year I teach a knife sharpening and tool making workshop in the bookbinding department at North Bennett Street School (NBSS) in Boston.  NBSS has the finest bench oriented two year bookbinding program in the world. If you have the passion, drive, commitment, dedication — and are crazy enough to pursue this antiquated profession in the 21st century — this is the place to do it. You will find many kindred spirits in your cohort.

I cover all aspects of sharpening related to bookbinding: blade angles, bevel angles, types of steel, types knives, types of grits, grit progression, hand grinding using power tools, free hand sharpening, and stropping. These techniques can be adapted to virtually any type of sharpening system: oil stones, diamond stones, waterstones, lapping powders and finishing films. Free hand sharpening throws many students into the deep end, for a while, but ultimately equips them to sharpen most types of edge tools. Most bookbinding knives have complex shapes and handles  which preclude the use of jigs or honing guides.

The foundation of this class is critical looking. Critical looking is not only closely watching the instructor demonstrate a technique, but it is looking at what you have done. Often when sighting or aligning, one eye is better than two.

Once you can visually analyze what your hands have done, then you can correct, alter, adjust, repeat your hand technique. Critical thinking is taught via writing in undergraduate curriculums. Could critical looking be linked to drawing?  Taking a photo or shooting a video can be a useful shortcut for note taking that may gloss over important aspects, such as processing and replicating. Drawing really forces you to look closer, again and again and again.

Critical looking is different from just looking. In a narrow sense it means learning to interpret what you are looking at, what the scratch patterns, reflections, divots, rounded bevels mean in relation to how you were holding the knife. In a broader sense it means understanding  what the effect of your actions are. Critical looking is the basis of all sharpening, maybe all craft skills?

 

Below are some images of the 2017 workshop shot by Brian Burnett.

 

All Photos Copyright 2017 Brian Burnett. And he was critically looking.

 

Thinking About Making: You, Artifact and Tool

tooluse
A work-in-progress diagram of the interactions that take place when performing a craft.

I’ve been thinking about using tools for a while now, starting in 2004 with a preliminary (and upon rereading inadequate) exploration in Vol. 1, No. 1 of The Bonefolder. Since then, the cultural literacy of tool use continues to decline. In fact, I often encounter people who think they can pick up any tool and it will work fine without any evaluation, prepping, sharpening, maintenance, etc.  If nothing else, thinking a bit more about tools before using them can lead to more successful craft outcomes.

This work-in-progress diagram summarizes some of my thinking. David Pye’s concepts of “workmanship of certainty” and “workmanship of risk” fit nicely into it; technique forms a continuum between you and the tool, not residing completely in one or the other. In paring leather, for example, using a schar-fix or Brockman paring machine involves relatively little technique from you, but resides mostly in the machine. Of course, you still have to know when to use it, and set it up and maintain it. Failure is often catastrophic, it usually works well or it doesn’t. This is the nature of the machine.

A middle ground between you and the tool might be the spokeshave.  Although a 151 spokeshave needs to be modified to work well, it is safer and quicker than using a French or Swiss knife to scrape the leather. It requires more skill to use than a paring machine, but accidents are usually small tears, or sometimes chatter, rarely catastrophic, can lead to uncomfortably small small pieces of leather.

The most risky way to pare leather overall is with a French or Swiss knife.  The locus of technique is almost entirely dependent on your skill.  It takes a steady hand and a lot of practice, but I have seen binders become suprisingly adept at it. Similar to the paring machine, failure can be catastrophic, like cutting a hole in the middle of the spine. All three of these methods of paring are not mutually exclusive, often they are all used by the same binder for various purposes at various times.

There is also room for conservation work in this diagram. Your intention on the artifact is much more limited due to ethical considerations about preserving existing information inherent in the artifact, there often has to be more creative thought put into material selection and tool use. If you are paring the leather on the original spine of a book that will be rebacked, there is little or no margin of error. A loss becomes a loss of information in the artifact. You can’t buy another one. Your tools have to work perfectly.

Materials also place limits on an original design. Often beginners want to experiment with something new, unique or unusual.  There is nothing wrong with this, but it is usually much more difficult than performing a craft activity in a more traditional manner. Unusual materials can require unusual tools.

One of the joys of craft is when the three elements in this diagram are so integrated that we think through the tool and into the artifact. It becomes embodied, a natural extension of our hands.  We often call this muscle memory, or getting a feel for something. Again to use a paring example, when you are competent, the leather pares down quite simply and easily without much conscious thought. When you first learn to pare leather, you need to conscious of how hard, soft, stretchy and thick the leather is, how sharp your knife is, the blade angle of the knife, the bevel angle of the knife, the angle you hold the knife at, where you start the cut, and the amount of leather you are cutting at one time.  This is a lot to keep track of.

I think many of us forget how much of an interplay there is between these three elements. It is important to remember that when things are not going right in any craft, it is not completely your fault, or the tool, or what you are making: it is usually an inter-relationship that can take some time to sort out. That’s one reason why we take classes to learn things.

To be continued….