Blade Comparison - A Blinded Study

If I didn't already have a lifetime supply of GSB blades, I'd get the Rubies in large quantities.

The price is about the same as Polsilver SI - but they seem to work really well with a variety of razors.

Great post. Enjoyed reading about the experiment and it's results. I may have to try this with my favorites, Voskhod and GSB. And a couple I don't think I enjoy as much, namely Polsilver, and Med Preps.

This is an intriguing and tempting scenario for a future blind test.

Such a methodology is preferred to knowing what blade you're testing because you have no preconceived bias associations either for or against what you are using. You are simply shaving and recording the feedback. Excellent!

Highspeedlane said:

This is an intriguing and tempting scenario for a future blind test.

Such a methodology is preferred to knowing what blade you're testing because you have no preconceived bias associations either for or against what you are using. You are simply shaving and recording the feedback. Excellent!

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My next experiment, which I will start after returning from a trip in July, is to limit the comparison to two blades (Polsilver v Rubie) but have my wife put the blade in the razor in a more random fashion. In the experiment that I just completed, I knew when I was shaving with a new/different blade. In this next one, I will have no idea if I am shaving with the same blade on consecutive days or if the razor is loaded with a different blade. I will probably limit the test to 4 shaves/blade so that a dull blade does not become an issue.

Should be interesting

An awesome (and yet simple) experiment. Thanks for doing this and inspiring others ... I'd love to see more unbiased data like this.

I've been part of an organized double-blind study. From the first round, I was surprised to see two blades that I thought I didn't like come up as my favorites

I look forward to seeing the results of your Polsilver vs. Rubie experiment ... but I would also really like to see if you could later replicate the results of your first experiment. Reproduced results would help to confirm that untracked, potential variables didn't influence the outcome (like diet, exercise, etc). And perhaps most interestingly it would help to confirm that manufacturers do a good job at controlling the variance in their blades.


Thanks for taking the time to do this and share the results! As soon as I complete the study that I'm in, I'll likely do a series of experiments like this myself.


Cheers,
Shawn

shawnsel said:

Reproduced results would help to confirm that untracked, potential variables didn't influence the outcome (like diet, exercise, etc). And perhaps most interestingly it would help to confirm that manufacturers do a good job at controlling the variance in their blades.

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Shawn,

I was concerned about untracked variables as well. In particular Blades #2 came after a very disappointing blade. I was concerned that since blade #1 caused irritation and weepers, Blade #2 was working in a difficult environment. Blade #4, my favorite, never had that issue. In part that is what has motivated me to do the second study. The random choice of blades should eliminate that bias.

As for quality control from the manufacturers, you bring up an interesting point. There are several blades out there that are well liked that have not worked well for me. The top one that comes to mind is the Personna Med Prep which was a terrible blade for me. I have always wondered if I purchased a bad batch, but there is just not enough time to test and then retest a blade from a different lot.


It is Impossible to Teach an Old Dogma New Tricks.
-Dorothy Parker

She is a GEM! Congratulations on a GREAT POST!!! Love the methods and non-biased results.

stovepipe699 said:

Are Gillette Rubies still in production?

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I just got some from TryABlade.com. They were, unfortunately, 65 cents each for 5 blades. And, now that I think about it, that's just about what it costs for a cartridge that would last me as long (or longer) than 5 blades, I think. Hmm.....

StuartV said:

I just got some from TryABlade.com. They were, unfortunately, 65 cents each for 5 blades. And, now that I think about it, that's just about what it costs for a cartridge that would last me as long (or longer) than 5 blades, I think. Hmm.....

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Try a blade isn't meant to be used for bulk purchasing, but for sampling. What cartridges were you using that cost you only 0.65? I used Dorco for a while and I think they were still over $1.

gwsmallwood said:

Try a blade isn't meant to be used for bulk purchasing, but for sampling. What cartridges were you using that cost you only 0.65? I used Dorco for a while and I think they were still over $1.

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The Gillette Rubies. 65 cents per blade.

The most expensive blade on TryABlade is the Kai SS and it's only 85 cents.

Are you talking about being over $1 for 5? Before, I said the Rubies were 65 cents EACH for 5 blades. As opposed to what they might elsewhere (on a per-blade basis) for buying 50 or 100.

StuartV said:

Are you talking about being over $1 for 5?

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I was talking about Dorco Cartridges, since you said you thought you could get a cartridge for 0.65.

gwsmallwood said:

I was talking about Dorco Cartridges, since you said you thought you could get a cartridge for 0.65.

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Oh. No, I was saying that my normal cartridges (that I was using - Schick Quattro or Hydro 5) cost about the same as 5 of the Rubies (0.65 x 5 = $3.25 - so ROUGHLY the same) and would last me about the same time that I would expect to get from 5 blades (i.e. about a month).

IOW, it was my realization that if I make a habit of paying 65 cents per blade for DE blades, I'm not really going to be saving any money over how I was cartridge shaving before.

StuartV said:

Oh. No, I was saying that my normal cartridges (that I was using - Schick Quattro or Hydro 5) cost about the same as 5 of the Rubies (0.65 x 5 = $3.25 - so ROUGHLY the same) and would last me about the same time that I would expect to get from 5 blades (i.e. about a month).

IOW, it was my realization that if I make a habit of paying 65 cents per blade for DE blades, I'm not really going to be saving any money over how I was cartridge shaving before.

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Now that makes a lot more sense...

I paid $22 for 100 Rubies off Ebay. Not the cheapest, but not bad.

DesertJake said:

I paid $22 for 100 Rubies off Ebay. Not the cheapest, but not bad.

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Great price if it included shipping.

It did indeed. I offered the seller in Lithuania $44 for 200. It took a little while to ship, but they arrived just fine.

I've got some ebay bucks coming soon, so I may load up some more.

INTRODUCTION
rodmonster did a pretty convincing experiment comparing his favorite DE blades: the Polsilver SI, Nacet, Gillette 7 O’Clock Black, and Gillette Rubie Platinum Plus. He was surprised how hard it was to accurately distinguish between the blades. He also felt he may had been guilty of user bias.

I couldn’t resist. I had to replicate the study.


PROCEDURE
I used the following blades - the top performers on my B&B review:
http://badgerandblade.com/vb/showthread.php/460283-Cumulative-blade-review-a-non-blinded-study

• GSB (big favorite)
• Feather (big favorite)
• Personna Med Prep (big favorite)
• Personna Lab (okay…it’s not my favorite, but I was aching to see how it would fare in a blinded test against a Med Prep)

I followed rodmonster’s procedure as closely as possible using a 24-hour beard, and a three-minute prep with hot water. I used:

• An ATT razor with an H2 plate
• Cold Water Soap Works for lather
• Alum after shaving to give me extra feedback.

I wanted to answer two questions:

1. Would my blinded results be the same or different than my professed favorites?
2. Could I distinguish between the four blades at three and six day intervals?

This study was divided into two “flights” of shaves. On the first flight, I shaved with blades 1 to 4, and shaved with them three times each. (Twelve shaves total.) On the second flight, I shaved with blades 5 - 8 (which were actually the same four blades, but in a different order. Again, twelve shaves. My father randomly changed the order of the blades for each flight - a single-blinded methodology..

While doing these tests, I took some notes (which I’ve included parenthetically).


RESULTS
BLADE #1 of 4
Shave #1: Extremely, almost surgically close shave - but not really smooth. Some resistance ATG on the mustache. Not what I’d call a “comfortable” shave. Three light nicks. Alum “burn” after shaving that lasted over five minutes.
(I’m thinking, there’s no way this can be a GSB, and a Feather isn’t this harsh. It’s got to be a Personna.)

Shave #2: Another very close shave, an extremely sharp blade that mowed down my beard with ease; almost identical to shave #1. Like before, slight resistance ATG on the mustache. One nick on the mustache. Less alum sting, this time only on the mustache.
(My thoughts: It’s either a Med Prep or Lab. I can’t tell which yet, but I remember the Med Prep being smoother, Lab being rougher.)

Shave #3:
About the same as #2, except it’s ever so slightly smoother. One small nick, on the mustache (again). Same alum burn as shave #2. This blade is just now starting to dull a bit, at least based on the mustache test.
(Is it Med Prep or Lab? It’s fairly close, but the Med Prep is a little smoother than a Lab.)

BLADE #2 of 4
Shave #1: Very close, not completely smooth shave - except on the second pass, when I got three nicks (two on the lip, one on the chin) which required styptic. Shaving the mustache ATG is possible but not easy. Alum burn on my mustache and neck lasted around five minutes.
(Because of the nicks, it has to be either a Med Prep or a Lab. Feather and GSB are much smoother than this. I have my suspicions, but let’s wait until tomorrow to narrow down the suspects.)

Shave #2: Fairly close close shave, though there’s ever slight resistance, particularly on the neck. Two very light nicks near the lip. Shaving ATG on the mustache is still possible, though with irritation. Alum burn that’s strongest on the mustache, and lasts for ten minutes.
(Definitely Personna, but it’s still hard to pick which blade. I remember Med Prep being more “clinically” close - whatever that means. )

Shave #3: The blade is starting to lose its edge; it takes longer to shave, and the shave itself is slightly less close, especially on the chin. Two nicks: one on the mustache, the other on the chin. Shaving the mustache ATG is no longer possible, though other strokes are possible. Alum burn was very sharp, but subsided after five or so minutes.
(The Med Prep and Lab are similar in their aggressive sharpness, but this blade is really starting to lose its edge. I think it’s a Lab.)

BLADE #3 of 4
Shave #1: Very close, but smooth shave. Slight stubble on the chin, neck. While shaving, the sound was almost musical as the blade mowed down the beard. Slight resistance ATG on the mustache. Alum burn on the mustache and neck lasted about five minutes, then subsided.
(My thoughts: American Personna blades are a little rougher than this. The overall smoothness and closeness bring up two candidates: GSB and Feather. I can’t tell the differenquite yet, but I remember the GSB is the smoother of the two blades.)

Shave #2: Comfortable shave, but not that much closer than normal. Mustache ATG is the same as before - fairly smooth. Chin was closer than shave #1. Three small nicks - two on the mustache, one on the neck. Alum burn on the mustache lasted over five minutes.
(Most probably a Feather. Still has lots of sharpness, but it’s relatively forgiving. But over-shaving can cause razor burn with this blade.)

Shave #3: Same closeness as the last shave. The mustache, this time, shows some resistance ATG. No nicks or cuts. Slightly less alum burn than before, but it’s still a close shave.
(Smooth, with an edge of sharpness when using pressure. I’m guessing Feather.)

BLADE #4 of 4
Shave #1: BBS shave, exceptionally smooth, no nicks or cuts. One minute of alum burn after shaving.
(GSB.)

Shave #2: BBS shave, smooth as before, but slightly more resistance on the whiskers. Two small nicks: on the lip and neck. Three minutes of alum after shaving.
(GSB.)

Shave #3: BBS shave, another smooth shave. One nick not he lip. Took a little more time cleaning up after the second pass. Chin could be cleaner. Two minutes of alum after shaving.
(GSB.)

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PREDICTIONS ON BLADES #1-4:

Blade #1 is Personna Med Prep (CORRECT)
Blade #2 is Personna Lab (CORRECT)
Blade #3 is Feather (CORRECT)
Blade #4 is Gillette Silver Blue (CORRECT)

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BLADE #5 of 8
Shave #4: Near-BBS shave, except for slight stubble on my neck. No nicks or cuts. Four minutes of post alum burn.
(Smooth and sharp. Obviously a GSB.)

Shave #5: BBS shave, no nicks or cuts. Three minutes of post alum burn. At the end of the day, I noticed that the shave didn’t last through the next day. That’s interesting, because the shave itself was outstanding.
(GSB.)

Shave #6: Near-BBS shave, no nicks or cuts. I can still shave the mustache ATG - something that’s difficult with most blades. Three minutes of post alum burn.
(GSB.)

BLADE #6 of 8
Shave #4: Astonishingly close, but a little harsh. There’s some resistance ATG on the mustache, but only one side. About five minutes alum burn on the mustache and neck.
(My thinking: Somewhat harsh but incredibly sharp. It profiles like a Personna Med Prep, but the added mustache resistance throws me. Is there some wear already?)

Shave #5: Exceptionally smooth shave, sharp blade…but no nicks. It’s not easy to shave the mustache ATG, but otherwise, the shave is especially close. Slight irritation on the entire mustache. Familiar alum burn on the mustache and neck.
(Feels just like a Med Prep. The combination of relative harshness and closeness is hard to forget.)

Shave #6: The cheek shaves smoothly, but there’s slightly more stubble on the chin and neck. Shaving the mustache ATG is nearly impossible, and there’s some roughness. No nicks, cuts, or alum burn.
(This blade is starting to degrade, though there may be a few more shaves in it. Med Prep.)

BLADE #7 of 8
Shave #4:
Smooth, clean shave aside from a light stubble on my chin and neck. Shaving the mustache ATG on the first pass is difficult, but just possible on the second pass. Alum burn on the mustache and neck for about five minutes.
(I can cross off the Personnas immediately…a GSB is smoother than this. It’s got to be a Feather. Sharp but kind of smooth.)

Shave #5:
Beard results are the same, but the blade doesn’t glide as quickly or easily as before. No nicks or cuts. Alum burn disappears within seconds.
(Feather.)

Shave #6:
No cuts or nicks, but the shave took about a minute longer this time. Mustache is close, but the XTG strokes took extra care; the second pass was clean. Alum burn diminished in about five minutes.
(Feather.)

BLADE #8 of 8
Shave #4: Quite close, but kind of rough. The blade labors over stretches of beard it would have sliced through before. WTG shaving on the mustache is easy, but the second pass turns into a third and fourth pass before I get a clean shave. Alum burn on the mustache mainly, and lasts about five minutes. By this point, I would have tossed the blade, but I’ll stick with the procedure till the end.
(This is so obviously a Lab it’s shocking.)

Shave #5: Very close, and kind of painful - especially on the mustache and neck. It takes at least four passes on the bristly parts of the beard. But the beard shaves clean (after some effort). No cuts or nicks. Alum burn lasts over five minutes.
(Lab.)

Shave #6: With application, the beard shaves pretty close, albeit with added pressure on the mustache, chin, and neck. No nicks or cuts, though the over-shaved parts of my face felt a bit sore because of over-shaving. Alum sting lasts over five minutes.
(Lab.)

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PREDICTIONS ON BLADES #5-8


Blade #5 is Gillette Silver Blue (CORRECT)
Blade #6 is Personna Med Prep (CORRECT)
Blade #7 is Feather (CORRECT)
Blade #8 is Personna Lab (CORRECT)

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DISCUSSION
I wanted to answer two questions:

1. Would my blinded results be the same or different than my professed favorites? Yes. The blinded results have been confirmed.
2. Could I distinguish between the four blades at three and six day intervals? Yes, I could, but my second flight picks were even easier.

The most interesting part of the test was the comparison between the Personna Med Prep and Lab. For the first two shaves, the blades seemed quite similar (but not identical): sharp, and a bit abrasive. (The Med Prep seemed to come up with somewhat closer shaves, though I can’t quantify the difference.) From the third shave, the Lab lost some keenness, and I considered tossing the blade by the fourth. The Med Prep stayed pretty sharp through six shaves, despite some gradual loss of sharpness.

Some claim there’s no difference between a the Med Prep and Lab; but I disagree; there’s a pronounced difference.

If the difference is so obvious, why is there still so much controversy on this issue? The most obvious explanation may lie on your choice of razor; an aggressive razor can make a Personna feel almost painful, while a mild razor can be very smooth. Same blade, different razors.

There’s another reason, too. Many shavers use a blade for only two or three shaves - before blade wear becomes really obvious. The longer you use a blade, the more chance of noticing issues related to wear.

There’s a lot of some good information out there relevant to the "Med Prep vs Lab" debate. If you analyze the composition of both blades http://badgerandblade.com/vb/showthread.php/386550-Scanning-Electron-Microscope-Blade-Edge-Images
...the numbers are extremely close. This suggests - as others have said repeatedly - that they’re basically the same blade...albeit with some kind of additional treatment.

The Med Prep and Lab have similar tolerances, and are made in the same factory. But they're made on different machines by different Personna divisions. The Med Prep is made in the Medical Division, while the Lab comes from the industrial division.

The folks at Electron Microcopy Sciences say that the Lab is PFTE-coated (Teflon), while the Med Prep is washed and degreased to minimize foreign matter on the blade. Personna has confirmed this.

My blinded research indicates that the blades have notably different performance, particularly from the third shave on. If you’re interested in replicating the results, it’s ideal to use an aggressive razor. (An ATT with an H2 plate, a Muhle R41, or Fatlip are good choices.) It’s almost as important to allow for an extended trial of five or six shaves.

I don’t know exactly what made the two Personna blades so different…only that the difference can be quite pronounced. In another blinded study, B&B member Oscroft agrees. http://badgerandblade.com/vb/showthread.php/305863-Blind-test-9-Personna-Med-vs-Lab (Note that Oscroft used a Edwin Jagger razor, but came up with similar results.)

Why are my results so good? First, the four blades are relatively unalike. The GSB is a very distinctive blade (ultra-sharp and very smooth); the Personna Med Prep is ultra-sharp but a little rough, while the Lab starts off rough and gets rougher; and the Feather is exceptionally sharp and long-lasting, but definitely not harsh. An aggressive razor like an ATT H2 magnifies their characteristics. (I’m not sure I'd be able to detect these differences with a mild razor like, say, a Gillette NEW.)

Second, the intervals of three and six days clinched my guesses. After six days of shaves, it was easy to distinguish between the blades by blade by comparing wear patterns alone.

Finally, extensive experience evaluating blades has forced me to come up with special criteria (like mustache closeness, relative comfort, speed of shave, alum burn, beard resistance - both WTG and ATG). Shaving-wise, I’m probably no more perceptive than the next guy; but I do pay attention to specific signposts while shaving.

All that said, this is an informal test with rather limited scientific value. While the use of rudimentary controls and simple statistics will be convincing enough for most, even simple statistics can be deceptive. For example, rodmonster’s rankings seem, on the surface, to be totally inaccurate (0/4 correct)…but in actuality, they're fairly accurate. (rodmonster’s ratings of individual blades are rarely more than one place away from expected results.) One could get more sensitive results with a Spearman Rank Order test and a larger pool of subjects.

Sounds like a good reason to replicate the study!

poikkeus said:

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PREDICTIONS ON BLADES #1-4:

Blade #1 is Personna Med Prep (CORRECT)
Blade #2 is Personna Lab (CORRECT)
Blade #3 is Feather (CORRECT)
Blade #4 is Gillette Silver Blue (CORRECT)

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PREDICTIONS ON BLADES #5-8


Blade #5 is Gillette Silver Blue (CORRECT)
Blade #6 is Personna Med Prep (CORRECT)
Blade #7 is Feather (CORRECT)
Blade #8 is Personna Lab (CORRECT)

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I'm impressed with your correct (blinded) identification of 8 out of 8 blades! Much better than my own.

You know, perhaps treating this like a contest might encourage more people to collect and share blinded blade data? Perhaps those who can identify a certain number could be dubbed with a special title?


Cheers!
Shawn

@Poikkeus

Great work and it seems as if you had as much fun doing a blinded test as I did. Congrats! on being able to identify the blades correctly (I could not). You did confirm one of the unexpected findings of my study: Prior to my study, based on years of experience with these blades, I would have said that the differences between the blades were small. Once blinded to the blade in the razor, the differences were highly magnified and the difference in quality between my favorite blades (Gillette Rubie; Polsilver SI) and the laggards (Nacet; Gillette 7 OC Black) was quite large, so large, in fact, that I have not used a Nacet or Gillette Black since the experiment. They have been relegated to the back of the shelf.

I do suggest that everyone try a blinded study even if only on a small scale. Not knowing which blade is in the razor adds a great deal of intrigue to a shave. There is a heightened sense of awareness with every stroke of the razor. And, as a bonus, the results may even surprise you.

I congratulate Poikkeus for his great contribution.

You guys make a good point: it doesn't take much more time to come up with a simple study - but others will be more confident with your results. What's more: the whole process is fun, and makes shaving more enjoyable.

Why not, for example, pit the Rubie (which I haven't tried yet with a GSB?