I was recently asked the question: if I use a Mach3 razor, is that the same as doing a three pass shave?
The answer is no, but it’s a good question. Another time I might do an actual result comparison by doing by, but for now I’m just going to explain the difference. For those unaware, this is a Mach3 razor:
It has three blades mounted in succession, the idea of which is to give you tree cuts at the hair with one pass. It’s understandable why one might think this means that one pass is the same as three passes with a safety razor. But it’s not.
The primary difference is that a Mach3 cuts the hair in the same direction with each blade, while a three pass technique with double-edge (DE) safety razor is generally considered to involve one pass with the grain, one pass across the grain, and one pass against the grain.
Why is this important?
When a razor connects with a hair the hair resists. When you shave with the grain the hair has more opportunity to bend when pressed by the razor, which reduces the closeness of the shave. By gradually increasing the hair’s natural resistance to the blade by moving across and then against the grain, while at the same time reducing the hair’s length with each pass, it allows you shave optimally against the hair on the final pass while reducing the likelihood of irritation, unevenness, or other problems associated with shaving against the grain outright.
A Mach3 can also be used this way, of course. In fact, pretty much everyone I talk to that uses a multi-blade cartridge ends up making at least two passes with it (one with and one against the grain). However, you are then making just as many passes as with a DE razor, meaning you’ve now had nine blade passes over the hair.
That’s if the later blades are even connecting properly, of course.
The secondary benefits of multiple passes with a DE razor over one pass with Mach3 is that it allows the hair time to recover, while also ensuring that each time your blade is passing it is at a pressure and angle that you desire. If the hair bends while being cut by a Mach3, there simply isn’t much time for it to straighten before the second and third blade hit it. But by giving it time while you complete your first pass, lather, than shave up to the location again, you allow more time for the hair to recover, which in turn improves your ability to shave it.
And of course, one of the best benefits of the three pass method with a DE razor is that DE shaving is a lot of fun, and it gives you more opportunity to enjoy it!
So that’s the difference. It boils down to the fact that each pass of a three pass technique is intended to be different than the first, while each blade of a Mach3 is supposed to do the same thing as the others. If that works for you, good deal.