Angles And Perspective

Why is shaving considered an art? Why can't it be a matter of science, or at least math? I've watched my colleagues in the blogosphere (some of whom I hold in high regard) grapple with the geometry of DE razor heads, nobly pursuing hidden truth. For the sake of predicting shaving character, I've made a few gross generalizations in that vein, myself.

But there is obviously a bigger picture to be considered, in the interaction of razor with skin and hair. If a tangential line between the top cap and the safety bar actually defined a "shaving plane," anything with positive exposure would be a bloodbath. My beloved "mild" razors would never give me my accustomed, smooth shave.

If one puts too much faith in such pure rationalizations, mere technical improvement falls by the wayside. Useful techniques can be excluded on rational grounds. The "no pressure" rule, for example, is a direct behavioral consequence of the aforementioned "plane" concept. When one fails to achieve a close shave in those terms, still there is only one variable to alter, and so... "YMMV," it ends poorly.

Below, I have attempted to encompass the relevant points of geometry in shaving, sweeping an arc of DE technique. It is an exercise in imagination. The razor has been called our earliest nanotechnology, using normal-scale controls to manipulate face and beard at a microscopic level. The art consists of inferring the unseen connection, using our most sensitive perceptions and finest motor skills.


It has also been suggested that cavemen used clamshell tweezers on their facial hair. I think the argument can be made that a prior caveman sharpened the edge of his shell and gave himself a proper shave. Maybe he stropped it by accident while making his animal-skin clothing. Maybe he laid a thicker shell behind it for support. Maybe there was even a third shell ahead of the first, to protect his leather. Of course, this caveman never amounted to much, other than to woo the cavewomen and populate the planet. It was another, less talented hominid, one with marketing skills, who witnessed his activity and invented the tweezers.

There really is nothing new under the sun, with respect to shaving. You lodge the edge of something sharp into the base of a hair, carefully, at an angle that won't cut the skin. You hold the skin under the blade taut as necessary, so the caught hair can't slide forward; and you push the edge through the hair, scraping it off. It is less harmful than pulling out the hair. It is more satisfying than shearing the hair above the surface of the skin, where it is still palpable to touch.

The edge of a blade features the primary geometric structure in shaving: an acute angle. At the tiniest scale, material on either side of the apex is bent and stretched until it pulls apart. Then, the sides act as a wedge, making further progress of the edge much, much easier.

When choosing a blade, consider how coarse the hair is. The coarser it is, the more acute the edge should be. The impact required to initiate the cut will be distributed across more surface than it would be on wiry hair. Vertical displacement will need to occur more gradually, too, in order to prevent the edge from torquing through the cut in the wrong direction, lengthwise up the hair -- or worse, down into your skin. On the other hand, less sharp ("smooth") blades offer a wider range of skin-safe cutting angles and more wedge force. Until they are too dull to initiate the cut, at which point they chew and distort the skin with a "distressed leather" effect.

Extra bevels or ground curves recombine the desired qualities; the steel can be composed differently for durability; and a variety of smooth coatings exist, yielding the great diversity of DE blades available.


Truly, they are the ideal token of human development. I'm pretty sure Stanley Kubrick modeled the monolith from "2001: A Space Odyssey" on a DE blade. And if I ever descend from a tete-a-tete with the Great Other of shaving, the first commandment etched in fog on your mirror will be this:

Shave with the grain, until you learn the grain.

Knowing how oats and beans and barley grow (and evolve) isn't the point. Hair emerges from the skin at an angle. The cutting head of a DE razor is designed so that, when the breech is casually laid to your skin, the edge will meet that angle squarely. But only if it is oriented to the direction of growth. So when we talk about shaving with the grain, it isn't just a precaution for the sake of skin, that makes shaving less efficient. We're really taking a first pass at optimizing the blade orientation with respect to individual hairs.

Pressing the skin behind the stroke is especially advantageous when shaving with the grain. Not only does it hold the hair stationary; it torques the hair upright, rather than twisting it. A satisfactory shave in one pass is possible for some people, without invading the follicles at all.

Some instructors (wisely) leave it at that, but directions are usually also given for subsequent passes. Better to learn the principle: never allow the blade to gain excessive traction on the skin. Since the stratum corneum has no nerve endings, there can be no immediate, definitive feedback for mistakes of exfoliation.

On the other hand, "against the grain" is really just the other way that is in line with the grain... of course, it is inevitable that you're going to go for it! Remain mindful, and you'll connect your actions with the consequences, eventually.


While there are many odd hairs that do not cooperate with the whole "grain" thing, vast numbers often arise at a vertical angle that the razor design failed to anticipate. These are relatively well organized and easily provoked to violence. Well, you started it! And they finish it, with a sort of microscopic jiu-jitsu that turns the blade back on you. Who hasn't had a bad experience going against the grain on the neck?

Lay a non-serrated, flat blade on a flat patch of skin, and you should be able to slide it around in any direction. That is the idea of the "shallow angle" approach. Only one side of the edge displaces skin, so the skin cannot be divided. The "steep angle" is a bit trickier, with the blade aimed nearly straight toward the skin. But because no downward pressure is applied, and the blade is constantly moving, again, only one face of the edge applies to skin. Hair is caught, however, as it bends into opposition.

A firm grip is beneficial at either extreme, because the imbalance of forces on the edge is destabilizing to the cut. At normal, moderate angles of attack, be relatively gentle, for at that pitch, the edge is poised to cut skin, too. If your skin is tough, you might get away with using a twiddly grip, allowing the razor to find the moderate angle that is most efficient at cutting hair. We who cannot use cartridges are safer introducing that degree of freedom in the form of "blade flex," while maintaining a rigid, low-angle approach. Wiry hair, hard but thin, will still be unable to escape by bending over backwards.

As the edge wears, it becomes more and more difficult to bring both faces into effective opposition to the hair. High and low pitches converge, becoming the same, moderate angle. Once again, the skin is threatened by downforce.


The best way to mitigate the hazard is to introduce a slicing action, by rotating the razor handle slightly on its axis with your fingertips. Skew lowers the effective pitch of a low angle even further and presents a more acute edge to the hair. Steep angles can also be accentuated, making them safer (provided there is an effective safety bar, also). Analogous to the yaw of an aircraft or a boat, one can think of oblique strokes as either a skewing of the line defined by the edge length, or a sliding away from the usual direction of travel, perpendicular to that line.

I recommend starting near the facial midline, where the hair is toughest. Maintain constant opposition of the edge to the grain, and alter the usual WTG direction to better navigate the obstacles, more N-S. Out at the jaw corners, one has to balance the drag of the slicing action and resistance to the chopping action more subtly, by feel. Cleaning the fine curls under my ear is what I would call "the master stroke." Movement lifts the hair from its emergent angle close to the skin, while the skew is poised for the moment of maximum tension, more in line with the hidden angle of the hair root.

One of the great ironies of my experience was finding myself, after years of research, beginning my shave exactly as prescribed by the old Gillette instructions! And realizing that practically no one shaves that way. So, if you don't get it right away, not to worry. We'll be coming back to "the touch" in a later disquisition.

Full circle

When none of these angles on shaving succeed in either comfort or closeness, your blade is "dull." It is certainly better to ascertain the state of wear on a gentle, WTG reduction pass than to force it through extreme performances and count the cost to your skin. Finish with a little extra leverage and skewing to even it out, and leave it. The day will dawn on a better shave.

That said, the extreme variability among shavers with respect to blade longevity, from one use to 30 or more, is not so much attributable to variations in beard toughness or brand superiority, as it is to technique. The inherent danger of moderate angles of pitch is why beginners are often advised to change blades after only a few uses. You will improve to a point where you needn't throw away a blade unless it fails to cut hair.

Read on to discover the principles that allowed "10 to 40 velvety shaves, without stropping" before blades were even made stainless!