The Intelligent Chef: Cutting Boards

Government’s first duty is to protect the people, not run their lives.

President Ronald Reagan

This article is about the cutting board, a tool every household contains, but about which relatively few have given serious thought despite it’s constant role in our lives and the potentially huge negative health impacts it sometimes conceals.

Civilization’s Ultimate Tool: The Knife

Some anthropologists have asserted, and with good reason, that the food-preparation knife is not only the oldest, but the single most important tool ever invented by the human race, increasing populations, improving health and longevity, and saving many hours not only in harvesting food, but in making it edible, nutritional and safe to eat.

We will discuss kitchen knives in a separate post, but because a food-preparation knife without a cutting board is less than 100% effective, I will focus on cutting boards in this article.

Cutting Board Materials – Plastic vs. Wood

Allow your humble servant to begin this article by urging Gentle Readers to please use wooden cutting boards in their kitchens.

But before we dig into to the engineering aspects of cutting boards, I would like to make an observation (maybe even a rant) about modern societal trends that have influenced health and safety laws. I beg your kind indulgence.

As I grow older I am constantly amazed at how many people are blithely immune to facts in both their private lives and public duties, and proud as a peacock of it. They demand that their uninformed opinions and personal biases be given precedence over both actual, verifiable evidence and the scientific method, and call anyone who disagrees with them fascist and/or anti-science. Talk about psychological projection.

A recent example of this tendency in the United States is the strange idea that requiring voters to provide personal ID when voting is both unnecessary and “obviously” voter suppression, implying that minorities are either too lazy or too stupid to obtain and keep track of such ID, an insulting, racist, and demonstrably false supposition. Anyone who made such an assertion 20 years ago would have been universally viewed as either corrupt or mentally deranged. What does it mean that, during the last 4~6 years, top leaders of the US Congress and Senate as well as the top executives of major corporations routinely insist this strange concept should govern elections?

Political gamesmanship aside, some health professionals blame this form of brain damage on social media, but it is an unfortunate tendency that was around even before Twitter and facebook.

What people believe in their private lives is up to them, but to allow such tendencies to rule public policy and determine regulations with possible health and penal consequences is a big step back towards barbarism, IMHO.

Sorry, I almost fell of that damned soapbox and broke my silly neck again! Back to the subject at hand.

I am fully aware that many governmental health agencies in advanced countries around the world require commercial kitchens to use non-porous cutting boards made of plastic, HDPE (high-density polyethelene) or other synthetic materials. Like much of what is claimed to be hard scientific fact nowadays by incompetent, lazy, illiterate, irresponsible, unaccountable bureaucrats who then make regulations with teeth based on their poor understanding of unverified results produced contrary to the scientific method, the ban on wooden cutting boards too is based on nothing more than a casual supposition rather than verifiable facts.

This webpage summarizes this fubar beyond all doubt.

Your humble servant first became aware of this cutting board contradiction when I asked sushi chefs in Tokyo some years ago why they used wooden cutting boards in full view of customers instead of the more sterile-looking white plastic boards seen in the commercial kitchens I had constructed over the years. Their response was eye-opening.

Their first point was that wooden cutting boards are easier on their valuable knives keeping them sharper longer. That makes perfect sense, depending on the wood, of course.

Their second point, that wood is simply more sanitary than plastic, shocked me.

Now I know for a fact that the Japanese health agencies that regulate commercial kitchens are very strict about food safety, and that compliance costs commercial kitchens tons of money for special health & safety related equipment. I also know that most commercial kitchens in Japan do indeed use HDPE cutting boards. So why would sushi restaurants that serve raw fish and shellfish be different?

During subsequent conversations over several years with government health agencies, kitchen designers and subcontractors involved in obtaining kitchen permits and inspections for my construction projects, I asked them this same question. One gentleman responded by showing me the studies that formed the basis for health regulations for cutting boards. I have since done more research.

The essence of the concern about the safety of cutting boards in general is that liquids and particles of food, along with bacteria scrambling around on those foods and floating in the air in even the cleanest kitchen, not only spread over the surface of a cutting board in-use, but soak into the many cuts left by knife blades. In the case of wood, these may soak into the wood fibers too. Yuck, right?

Whether made of plastic or wood, liquids, particles and bugs can and do interact on the board’s surface where bugs make lots of baby bugs. Yes, that’s right: bug orgies on your cutting board! Double yuck!!

If the surface of the board is left wet and dirty for long, bacteria can multiply to dangerous levels to contaminate foods placed on the cutting board and later consumed causing food poisoning. BTW, most cases of food poisoning occur when eating out.

Try as we may, we cannot escape microbes and viruses entirely. They contaminate the surface of cutting boards regardless of both our caution and the cutting board material. The only workable solution to the sometimes lethal danger bacteria pose, short of working under burning UV lights, irradiating all foodstuffs with Gama rays (yes, that’s a real thing) and working in a cleanroom periodically drenched with anti-bacterial chemicals, is to limit their numbers and their growth so we can avoid ingesting more than our immune systems can safely deal with.

The misunderstanding that became the basis for health regulations in some areas outlawing wooden cutting boards in commercial kitchens started honestly enough with the observation that bacteria find their way into cuts below the surface of cutting boards and can potentially increase to dangerous levels. But the undeniable fact is that the researchers tested non-porous materials, not wood. Their reason for objecting to wooden cutting boards was based on an assumption, which they did not bother to check, that because wood is more porous than plastic, the bacterial infestation in wooden cutting boards must of course be much much worse than plastic. Government health agencies responsible for making kitchen regulations took this supposition at face value without bothering to do more thorough research. The earth is flat because, well…, it makes sense.

To make wise decisions about materials, responsible and intelligent people always obtain a sound understanding of the materials in question, something the advocates of plastic cutting boards fail to consider. So let us bravely examine plastic cutting boards and wooden cutting boards from a microbe’s eye view.

The first difference between plastic and wood is nothing less than a miracle of nature. Wood comes from trees which are, functionally, big waterpumps reaching up into the sky. Therefore, unlike plastic, which started life as black goo deep in the earth, living wood spends its entire life both wet and exposed to soil, fungi and bacteria. God designed trees and wood specifically to be resistant to fungi and bacteria, producing chemicals to fight them off. Even many years after a tree has been turned into lumber, these chemicals remain more or less effective at killing and preventing the growth of bacteria that cause food poisoning too. Microbes are offended by trees with such noxious flavors, and rightly so. I like my wood spicy. What about you?

Does plastic contain chemicals unpleasant to microbes? No, not unless someone applies them. Tabasco Sauce is a proven antimicrobial, BTW, although I am not suggesting Gentle Readers douse their plastic cutting boards with it, unless they REALLY like spicy flavors, a sure sign of a warm personality. (ツ)

There are of course antimicrobial chemicals, such as silver colloid compounds, that can be added to plastics to control bacterial growth for a time, but you don’t want them in your food.

The second difference between wood and plastic is found in the very structure of wood, because the cellulose tubes that make up wood are designed specifically for transporting water. Consequently, liquids that enter the wood through knife cuts tend to be wicked away and dry relatively quickly denying bacteria the moisture they need to grow out of control. The result is that bacteria in the knife-cuts in wooden cutting boards do not survive long, much less grow to dangerous levels. This assumes standard cleaning and maintenance, of course.

But wait a minute now. Plastic cutting boards dry out too right? Of course they do, but the sucky reality is that, while the surface of a plastic cutting board may be dry, the liquids, food particles, and bacteria inside the knife cuts, having fewer avenues for evaporation and/or dispersion than wood provides, remain wet for much much longer forming a pleasant environment for bacteria to continue their bug orgies and enjoy water sports. The Salmonella Water Polo Team not only kicks ass but is super horny! Goooo Salmo-!!

To eliminate bacteria inside cuts in plastic cutting boards one must either soak boards in chemicals such as chlorine that will permeate all the way into the cuts to kill bacteria, or subject the board to high temperatures almost hot enough to melt the plastic. While they may make your teeth whiter and your breathe less dragon-like, do you think chlorine or other bactericides will improve the flavor of your favorite sushi or salad? Tabasco Sauce might, but chlorine won’t.

In addition, plastic boards are demonstrably harder on the cutting edges of knives, dulling them much quicker than wood does, an important factor for professionals.

Assuming proper cleanliness procedures are performed regularly, a wooden cutting board is better for your health, better for your knives and better for the flavor of your food.

The Bacteria Water Polo League and Your Cutting Board

Although we don’t like to think about it, the fact remains that the materials we make our meals from contain bacteria, some more than others. This is why God gave humans stomach acid.

Heat kills bacteria too, which is why cooked food is much safer than raw food. Next time you belly-up to a salad bar in Bangkok or Beijing, Gentle Reader, think about the cleanliness of the water and fertilizer farmer Bui used to grow those veggies, and if a little heat might not be a good thing.

Chicken, beef, and pork are good examples of problematic foods because these domestic animals all live in feces-covered environments and have higher tolerances to microbes like Salmonella and E.coli than humans in advanced countries typically do. Chicken products from large industrial poultry farms are especially bad. Unfortunately, too frequently these killer fecal bacteria are transferred to meat and poultry when being processed.

According to WebMD, 83% of the chickens tested in a recent Consumer Reports investigation were contaminated with one or both of the leading bacterial causes of food-borne disease — salmonella and campylobacter. Most of this bacteria was found on the chicken’s skin. As someone who has repeatedly suffered painful and debilitating food poisoning from eating contaminated chicken, believe me, Fuzzy Freddie Nietzsche was absolutely wrong because, while salmonella poisoning may not kill you, it won’t make you stronger but will just make you wish you were dead. Seriously.

The Salmonella Water Polo Team kicking back between matches and bug orgies
The screwy Campylobacter Jejuni bacteria cause most food-poisoning cases.

What does all this have to do with cutting boards? Let’s take a common, real-world example.

Say you cut up a chicken for a barbecue using your favorite knife and cutting board. The heat of the grill will kill salmonella, but the bacteria on the chicken skin will have transferred to and remained on your cutting board sure as eggses is eggses.

Now that the chicken is cut down to size, shall we slice some carrots and celery for a dip, and maybe cut some tomatoes, lettuce, cheese and ham for a salad? Sounds like a yummy plan.

But wait a second, Gentle Reader. Do you think the Salmonella or Campylobacter microbes left behind on the surface of the cutting board by that bird-brain chicken will have all died and gone to bug heaven during the two minutes you were getting the lettuce out of the fridge? Not so much. And will either Water Polo Team call a time-out on the surface of board and refuse to transfer to the veggies you will cut on the same board and eat raw 20 minutes from now? See the problem?

There are three potential solutions to keep horny microbes under control. The first is to clean and sterilize cutting boards used to cut poultry or other meats with boiling water before using them to cut foods you will serve raw. I highly recommend this technique, and have made some proven suggestions below.

The second solution is to have two cutting boards on-hand, one for meat and one for veggies.

The third, more economical and space-saving solution is to have only a single cutting board but to designate one side dedicated for cutting meat and the opposite side for veggies and other foods that will be eaten raw. Not a perfect solution but it will help.

Wood Varieties for Cutting Boards

The Japanese are very particular about the taste of the food they eat. Indeed, they claim, and I wholeheartedly agree, that the steel of the knife used to prepare the food, and the sharpness of its blade, both impact the flavor of the food, especially foods eaten raw. This is something worth investigating for yourself if you hadn’t noticed it already.

It makes sense therefore, that the material the cutting board is made from can impart flavors good or bad to the food we prepare. So what are some good woods from the viewpoint of flavor, and why?

Hinoki Cypress

Many Japanese sushi chefs like cutting boards made of Hinoki wood, a type of cypress.

Hinoki is a beautiful, light-yellow colored wood that planes like no other wood in the world. It has a unique characteristic in that it reaches maximum strength approximately 300 years after being felled, which, when combined with the natural resistance of the wood to fungus and bugs, explains why Japanese temples and shrines last for so long. Amazing stuff.

It also contains essential oils that smell very pleasant, and make time spent in a Hinoki bathtub filled with hot water absolutely heavenly.

These preservative chemicals are effective at killing fungus and bacteria, but they also impart flavor to the food they touch, especially when a knife is making fine cuts releasing fresh volatile oils constantly. These essential oils compliment the flavors of rice and most varieties of fish used in sushi and sashimi. But not all foods.

And while Hinoki has layers of soft summer wood, it also has harder layers of winter wood that, while not as harmful to a knife’s cutting edge as is Douglas Fir, for example, are not ideal. So what are the other options in common professional use in Japan?

Willow

Willow wood is considered by many professional Japanese chefs to be the ideal wood for cutting boards. It is soft, easy on knives, and it has a neutral flavor.

Ginkgo Biloba Wood

A quarter-sawn cutting board of Ginkgo wood

Gingko Biloba, also called the Maidenhair tree because of the spreading shape of its leaves, is another wood popular with professional chefs for cutting boards. It is my favorite.

Called the ”Ginnan” or “Ichou” tree in Japanese and written 銀杏 in Chinese characters, it’s the official symbol of Japan’s capital city of Tokyo and is planted along many city streets in part because it is hardy, beautiful, and quite resistant to urban pollution. It is also the symbol of the Japanese university where I earned my graduate degree, and is included in the logo mark of C&S Tools

Despite being a huge deciduous tree, Ginkgo wood has a uniform grain with little difference between summer and winter wood, a feature that helps keep knives sharper longer. It is also flavor neutral. It’s cells naturally contain flavonoids (polyphenolic secondary metabolites) that are effective at reducing odors, rare in woods, and especially suited to food preparation involving strongly aromatic food ingredients such as garlic.

Ginkgo, Willow and Hinoki are the three woods Japanese professional chefs prefer for their cutting boards. We carry cutting boards made from Ginkgo wood, and highly recommend them based on many years of direct experience.

Cutting Board Maintenance

There are two aspects of maintenance Gentle Readers should consider. The first is keeping the cutting board clean and sanitary, and the second is keeping it relatively flat.

Cleaning and Disinfecting a Cutting Board

Obviously we need to keep our cutting boards clean and free of nasty bugs if we are to avoid tummy aches, diarrhea and expensive visits to hospitals, but there is more to proper maintenance and keeping them free of dangerous microbes than wiping them down after each use.

Unless your wooden cutting board becomes covered with oily, greasy stuff, don’t wash it with detergents or scrub it with cleansers. Detergents remove the natural chemicals in the wood that control bacteria. Cleansers do too, but they are much nastier because the hard particles they contain can become embedded in the wood dulling your precious knives and adding unpleasant chemicals to your food for a long time. This applies to plastic cutting boards too.

The best way to clean a cutting board of any variety is to wash it under running water while scrubbing it with a brush, and then stand it on-edge to air-dry. Running water combined with physical force is very effective. Air circulation is important when drying, as is sunlight.

I also recommend you pour boiling water on the board’s work surfaces after each use to sterilize them. Here is wisdom: While disinfectant chemical products packaged in colorful handy-dandy plastic bottles provide employment for thousands of marketing minions and make tons of cashy money for corporations, nothing you can use in a kitchen is more effective at killing bacteria and violating viruses than boiling water. Nothing.

Just place the board in the sink with one end elevated an inch or so to help it drain, and pour boiling hot water over it from a pot or tea kettle. Turn it over and repeat. Don’t dry it by wiping it with a cloth or paper towel, just let it air dry because any cloth you use will be less sanitary than the board is now. Nothing beats hot water or steam for open-air sterilization purposes.

Some people like to oil their cutting boards. Not a good idea, IMHO, because oil makes airborne dust and bugs stick to the cutting board.

Never use any wood finishes on a cutting board because the chemicals they contain are seldom safe to ingest, which you will.

If you don’t plan to use the board for more than a few days, wrap it in clean, fresh newspaper to keep dust and other contaminants off while allowing the wood to dry.

Flattening a Cutting Board

If you use knives on your cutting board, eventually it will become hollowed-out in the center, much like a sharpening stone. A hollowed-out cutting board makes it harder to cut foodstuffs quickly and cleanly.

Yet another advantage of the wooden cutting board is that you can re-flatten its surface and make it absolutely pristine with just a few passes of a handplane, making it once again a pretty, happy tool. Try that with a slab of plastic.

If you have a few minutes here’s an experiment you will find interesting. Use a hand plane to true the face of one wooden cutting board. Then use a belt sander or other abrasive tool to true the face of another. Then gently place a single drop of water in the center of each board at the same time. You will notice that the water drop stands proud of the surface of the planed board, while it quickly soaks into the surface of the sanded board. Which surface do you think stays cleaner and is less inviting to the Salmonella Water Polo Team?

And which surface has more knife-dulling, tooth-wearing abrasive grit embedded in it?

Cutting board maintenance is a good reason for owning and using handplanes even She Who Must Be Obeyed can appreciate.

Here’s how to efficiently flatten your cutting board. You will need a straightedge at least as long as the board, a handplane, a marking gauge, and a carpenter’s pencil.

You don’t want to unduly reduce the useful life-span of your cutting board, so plan your work to return the board to uniform thickness if you can. Examine the ends and sides of the board. Is it uniform thickness on the edges? Many are not.

Use your straightedge to sight the length, width and diagonals of the board, noting where depressed areas are.

Use your pencil to cross-hatch the surface of the board to help you check your progress. Remember to plane the high spots first and avoid the low spots until they are only a wood shaving’s thickness lower than the higher areas. While planing, periodically check the board using your straightedge and apply more graphite cross-hatching.

Once you have one side flat, use a marking gauge to mark the target thickness of the board on its edges. A guestimate of this thickness is fine, but if you want to get a precise measurement, fit feeler gauges between the straightedge and the lowest depressed area, and mark this thickness on the board’s sides and ends using a marking gauge.

I know it’s tempting to just shave wood as fast as you can, but with a little bit of examination, planning and layout, your cutting board will look and cut better and last a lot longer.

Or, if you have an electric thickness planer, knock yourself out. But carefully.

Conclusion

I will end this article with a question: In the case of cutting boards, which material is healthier, tastes better, is easier on expensive kitchen knives, more biodegradable, requires less energy and releases fewer carbon emissions to produce, and is more sustainable – petroleum products or wood? If the answer isn’t obvious, you may want to check your ID.

YMHOS

PS: We carry a special line of Ginkgo wood cutting boards. These are solid wood, not laminated. Most are quartersawn for stability. They make a great gift. If you would like to give one a try, please let us know in the “Contact Us” form below.

An avenue of Ginkgo trees at night in Tokyo

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may the Salmonella Water Polo Team forever have icky orgies in my cereal bowl.

The Marking Knife

A spearpoint marking knife

“Make sure that you always have the right tools for the job. It’s no use trying to eat a steak with a teaspoon and a straw.” 

Anthony T. Hincks

There are many varieties of marking knives used for woodworking around the world. In this article your humble servant would like to discuss the Japanese version.

We will begin with some definitions, followed by an explanation of the design details and structure of the tool. We will save the best for last by describing two subtle but effective professional modifications to improve the tool’s performance and the results produced.

Definitions

The Japanese marking knife is called a “shiragaki” or sometimes “shirabiki.” The characters used vary, but can mean “white pull” (白引き), which makes some sense, or “white persimmon” (白柿), which makes little sense, so I suppose the persimmon character is used as a phonetic substitute for “kaki” (書き) which means to write. I choose to write the word as 白書 so the Kanji translate directly to “white writing.” That makes more sense to me.

Such confusing substitutions are all too common in the Japanese language in the case of words with purely phonetic origins. The fact is that, much like psychologists, lawyers, and priests, the Japanese people enjoy confusing terminology. It’s an ancient habit that probably won’t change soon. I say this as someone that has been reading, writing and speaking the Japanese language at graduate school level for 45 years, been a resident of, attended school and worked in Japan for 30 years, and been married to a Japanese woman and had Japanese relatives for 43 years. I can get into serious trouble in the Japanese language.

Now that we are done with the Japanese language lesson, I will simply call this tool a “marking knife.”

The marking knife is used to cut thin, precise layout lines in a board’s surface, most often but not always at a 90 ° angle to the direction of the wood grain.

Every woodworking tradition I am aware of includes the marking knife, and regardless of their preferred style, anyone serious about woodworking will own at least one, and know how to use it.

Advantages

The marking knife has some advantages over other methods of marking a line more-or-less perpendicular to the direction of the wood grain. Here are a few:

  1. The line it makes can be as thin as the edge of nothing, achieving precision unapproachable by pencils, pens, scribes, sumisashi, inklines, chalklines, laser-sights, or even wishful thinking for layout in wood in the case of lines at more-or-less 90˚ to the direction of the grain. The line it makes, however, is not as easy to see as an ink or even pencil line, so it is not always useful for rough layout work;
  2. The line cut by a marking knife penetrates the wood’s surface providing a physical place into which the woodworker can index the edge of his chisel, or nicker of his plow plane or rabbet plane, or the teeth of his saw, or points of his divider quickly, precisely and confidently without relying heavily on Mark-1 Eyeball, improving the efficiency and quality of both his layout and fabrication efforts. The resulting time savings, improvement in accuracy, and reduction of eye strain the indexing benefits marking knife lines provide are huge.
  3. When making layout lines on perpendicular faces of a member, such as a table apron, for instance, after making one line on the reference face, the remaining three lines can be indexed and extended from each other with a marking knife, confirming the accuracy of the member’s dimensions and ensuring the tenon shoulders will be sawed accurately creating an excellent tenon, assuming the craftsman knows how to use a saw properly, of course.
  4. The line cut by a marking knife severs the fibers near the board’s surface helping to prevent fibers from being torn out of the wood avoiding a ragged cut with saw, chisel or router.

Are you convinced yet?

Design & Materials

Shirabiki Ura by Konobu

There are many styles of marking knives used around the world, and your humble servant has tried most of them at one time or another, but none that I am aware of are as simple as, or functionally superior to, the Japanese version.

Lacking a pretty, turned handle and looking more like a blackened steel popsicle stick than a finished tool, the Japanese marking knife appears unfinished, even barbaric. But despite its stark appearance, it’s a sophisticated design that employs superior metallurgical and blacksmithing techniques.

Like many Japanese woodworking tools, the professional-grade marking knife is made with a layer of hard high-carbon steel forming the cutting edge, forge-welded to a softer layer of low-carbon steel which forms the body of the tool. They are almost always flat, generally thin, and not especially wide tools. Perhaps 1/2 the length of one side is ground flat and bright and includes a hollow-ground depression called the “ura,” while the other side is plain and includes the cutting edge’s bevel.

Some marking knives, such as the photo at the top of this article, have a spear point or “kensaki” (剣先)meaning “sword point” which is convenient because the same knife can be used either left-handed or right-handed. Some people prefer this style, but in my experience it has limited usefulness. To each his own.

The demands on the marking knife in terms of sharpness, durability, and edge-holding capability are not as high as for chisel and plane blades. The better-quality ones are hand-forged of high-carbon steel and quality jigane, properly shaped and filed, and carefully heat-treated.

Because of their thinness, marking knives tend to warp badly during heat treat, and consequently demand either a blacksmith with good skills or the use of high-alloy steels that warp little. Even experienced blacksmiths end up with a few rejects due to cracking and excess warpage, which perhaps explains the relatively high cost of handmade ones. It has mostly been a tool made by specialist blacksmiths.

For this reason, and because the performance demands on the cutting edge are not severe, Blue Label steel is entirely acceptable IMO.

The Ura

I mentioned the “ura” above, but let’s examine it a bit more. Ura is a Japanese word written using the Chinese character  浦. It means a bay or inlet from a lake or ocean, usually without lots of rocks, and often with a sandy or gravelly shore. You can imagine why this word was employed to describe the hollow-ground depression in many Japanese woodworking blades.

In North America, similar curved surfaces and depressions were once called “swamps” even though they were made in metal. This term is obsolete nowadays.

The ura is what makes the Japanese marking knife superior to its Western counterparts for two reasons. The first reason is that the ura makes it easier to keep the hard layer of steel at the reference side flat. Second, in light of the hardness of the cutting edge layer, the ura makes it easier to sharpen the cutting edge.

Without the ura, the hard steel would be time consuming to sharpen and would tend to become rounded instead of remaining a flat reference face to index against a steel square or straightedge. It’s a subtle and clever design more sophisticated than its simple appearance suggests.

In use, the flat ura side is pressed lightly against the leg of a steel square with the point cutting lightly into the wood and the heel floating above. The blade is then pulled toward the user to cut the straight layout line.

Lubrication

I recommend Beloved Customer use an oilpot to lubricate the marking knife’s blade to reduce friction and wear between the blade and the square, as well as friction between the cutting point and the wood. Not only will  your square last longer, but your layout lines will be more accurate. Don’t believe me? Give it a try.

Recommended Modifications

Marking knives are simple tools for a simple job, but there are a couple of subtle improvements some advanced Japanese craftsmen, especially joiners, make that Beloved Customer may want to consider.

1. Habiki

The first improvement is intended to minimize one downside of the marking knife, namely its habit of shaving metal from the square or straightedge used to guide it. In Japanese this modification is called ” habiki “ 刃引き which translates directly to “ blade pulling, ” as in pulling the blade’s cutting edge over a stone to intentionally dull it. It is a term borrowed from the sword world.

The steps to accomplish this modification are as follows:

  1. First, sharpen the blade;
  2. Then, with the tool’s ura side facing you, stand the blade vertically on its cutting edge on the face of a medium grit waterstone or oilstone with the last 2~3 millimeters of the blade, measured from the tip, hanging off the stone’s side so the tip does not contact the stone;
  3. Finally, drag the blade towards you creating a flat on the cutting edge, while leaving 2~3mm of the blade’s tip sharp. Voila.

The dulled portion of the cutting edge will now be less likely to shave your square or straightedge, while the sharp tip will cut the wood and make a pretty, accurate layout line, assuming you do your job, of course.

I know that the idea of sharpening a good blade and then intentionally dulling part of the cutting edge sounds gaga. In fact, when Honda-san showed it to me, I thought the old guy was pulling my leg. But Honda-san was a master among masters, a man in his 80’s who had been making extremely high-end custom joinery since he was 15 years old, one who took his tools extremely seriously. In addition, he let me try his knife so I was quickly convinced.

Honda-san’s technique works, so gather up your courage and give it a try before allowing your inner-troll to embarrass you. I promise you’ll like the results and your square will thank you.

2. Tip Bevel

The second modification is also one Honda-san taught me. There are several ways of doing it, but the essence is to grind an angled flat 15~18mm long  on the top edge of the blade’s side angled away from the ura, ending at the cutting edge’s point. The goal is to create a very sharp “clipped” point.

This angled flat has three purposes: First, it removes metal that would otherwise get in the way of your clearly seeing the knife’s cutting tip. This is important because often a knife must be indexed off a tiny divider point’s mark or a previous layout line, for instance when marking the shoulders of a tenon on four sides of a stick of wood. Removing this unnecessary metal will make it easier to begin the mark exactly where it is needed.

The second purpose is to reduce the friction between blade and wood when cutting a layout line, thereby improving control like racing tires on a fast car.

And third, it provides a convenient place to rest your fingertip to better control the knife.

If you imagine this modification can’t make much of a difference, then your lack of experience is showing. How embarrassing >~(ツ)~<

The Square

I know there are those who prefer to use a wooden square for layout work, and others who like brass ones. Both work just fine with a marking knife until they don’t. You would be wise to consider using a hardened steel square, or better yet, a precision hardened stainless steel square with your Japanese marking knife; They simply last longer and stay straighter.

There are hardened carbon steel and hardened stainless steel combination squares and die maker squares available on the market, but I think they are too bulky and too costly for making simple 90° layout lines on wood.

Matsui Precision produces a series of excellent hardened stainless steel squares that are popular in Japan and well worth the cost. I have been using them for years. Send me a note if you are interested.

The Japanese marking knife is a great tool. Once you use one, especially after making the modifications described herein, you will wonder how you ever got decent layout work done before.

YMHOS

My old marking knife was hard on my eyes and fingers, but now I know how to fix it!

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. May my square always lie to me if I lie to you.