Friday, June 27, 2014

Harshness versus Aggressiveness in Razor Design

I have a manufacturing and quality background (among other things), and as a result, I'm well aware of old-school thinking in manufacturing that production volume and quality were opposing issues, requiring that a manufacturer strike a balance between quantity of units produced and quality of product. That is, we used to believe that if you wanted high quality, you would have to produce lower volume and vice versa.

We now know that's not true. Given proper manufacturing processes, both volume and quality can spiral upward over time.

The same concept applies to razors' shaving characteristics. In the DE-shaving community, there is much discussion about mild versus aggressive razors -- the implication being that mild equals comfortable and face friendly, and aggressive equals harsh, uncomfortable, and possibly blood letting.

I've even heard some describe a blade as aggressive, which is ridiculous. A blade may be sharp or not, smooth against the skin or not, relatively stiff or not; but aggressive, really, has no objective meaning; aggressive is a term better applied to razor design.

When it comes to razors, I've outlined ten characteristics of a razor's design (click here for that article), any of which might affect subjective quality of the shave. Some of these characteristics will affect the efficiency of the razor -- that is, how easily it mows down longer stubble or tough hair. What is important for the razor user and buyer to recognize is that an aggressive (high-capability) razor isn't necessarily harsh. For example, the Merkur slant-bar razors are highly capable and efficient, but in the proper hand (using light pressure and direct, non-oblique strokes) can offer a face-friendlly shave.

On the other hand, many razors that are considered mild shavers can be on the harsh side. Lately I've been using TTO (twist-to-open) razors as an example. I have several of these including a Gillette Slim Adjustable and Weishi 9306-f -- both have limited blade reveal (the amount of blade you can see when viewed from the razor  top), and the exposure (the degree to which the blade edge is within the protective cove of the razor's safety bar and top cap) on the Weishi is mild, and, of course, the Gillette can be adjusted to have a mild blade exposure. Yet even though these do or can be set to have non-aggressive shave characteristics, I find the shaves they give to be a bit harsh as compared to UTO (unscrew-to-open -- a.k.a. two- or three-piece) razors. And this applies to a wide range of UTO razors, from the not-aggressive Wilkinson Sword Classic to the moderate Merkur shaving heads (such as the 33C or 34C) to the hyper-efficient Merkur slant-bar razors such as the 37C.

Contrast different (exaggerated) blade angles:
Left is smaller angle (less harsh), right is
larger angle (more harsh).

The reasons for this disconnect between aggressiveness  and harshness of shave, in these examples at least, is due to the razor-design characteristic of blade angle in the razor head. (Again, refer to this article [click here] for more information on blade angle as opposed to blade slant.) Those razors such as the TTOs that have a flatter, larger shaving angle in relation to the shaving plane of the head are more prone to scrape at hair and skin irrespective of blade reveal and, to some degree, exposure. The UTO razors mentioned tend to have a steeper blade angle, which will tend to slice more and scrape less. It's a small difference, but I've certainly found it to be noticeable -- to the extent that I only use my favorite two UTO razors in my daily rotation, and use the Wilkinson Sword Classic as a travel razor.

[UPDATE: I have proven my TTO-blade-angle hypothesis to be incorrect. If a TTO shaves more harshly, I now think it is related to a positive blade exposure and, perhaps, a related blade-bar gap. But I have subsequently, upon further review, had a quite pleasant shave with my Gillette Slim Adjustable TTO razor -- although it was set to its most mild setting. The article on that shave will be published in early November 2014, but hasn't yet been published, so I can't link to it as of this update publication.]

So I know I can't change the world -- not even the world of DE shavers -- but I can at least make you aware that mild shaving doesn't always mean face friendly, and aggressive doesn't always mean harsh. To re-use the examples from above, the Wilkinson Sword Classic and the Weishi 9306-f are both mild-shaving razors, having limited blade reveal and limited blade exposure; that is, they have about the same degree of aggressiveness, which is not a lot. I can get the same degree of closeness in a shave with either. Yet, all other things equal, the Wilkinson gives me a more comfortable shave, due to the relative blade angles.

Similarly, my Weishi 2003-m TTO (to name a non-adjustable TTO; but it's the same for the Gillette Slim set to a mild-moderate exposure) and my Merkur 33C UTO razors are also similar, have moderate blade reveal and exposure, but I consistently get a more comfortable shave with the UTO, even though the closeness of the shave is about the same.

The take-away message here is that, if you have sensitive skin, whether you choose a mild or aggressive razor, you may get a more comfortable shave with a UTO design rather than TTO.

That's my opinion based on experience and analysis. What's your opinion?

Happy shaving!

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