Cutting toilet paper "on the bias"

H

HoB

Joined
May 12, 2004
Messages
2,611
I am sure this has been done plenty of times by other people, but I have come to like this as a very applicable test of sharpness.

Cutting "on the bias" is a chef's term which refers to cutting very thin slices of meat or fish (anything that has some "give"), by putting the blade flat on the piece to be cut and pressing the flat side down. Then, making a drawing cut you are able to cut very thin slices, controlling thickness with pressure.

Instead of meat (which I don't necessarily have on hand) I use toilet paper of the very soft, quilted kind. I lay the blade flat on top press down and try to get a nice, clean cut by slicing and pushing the blade slowly forward. You hold of course the paper behind the blade with the other hand, otherwise I would just slide around. Since I took the picture with the other hand, it is not shown. It is not the most demanding of tests, but I think it shows very applicable sharpness. Here is the picture:

In this case I had only 2-ply paper, so I folded it over once to give it some volume and some "give". I find it is a really useful test for kitchen knife. This is a Yo' that I just had sharpened so it was pressed into modeling. The cut should be clean, not torn or scratched with the tip, just like you would be cutting a thin slice of tuna or kobe beef :) (ok, ok, I've never had kobe, but that doesn't prevent me from picturing it :D).
 
That's pretty slick. One question - what's the knife you're using?

Thanks, DutchV

edit - Never mind; it's a Spyderco Yojimbo.
 
Neat test - TP is pretty tough to cut.

That's a Spyderco Yojimbo. A great box cutter! Looks sharp, too.
 
It is not that difficult a test. All the blades that will pushcut free standing paper will do this. But that wasn't really my point. I think it is a good sensible sharpness that marks, at least for a kitchen knife, a very sensible level of sharpness. You can continue on beyond that. Also I think, unlike the standing paper push cut it work better with a blade that has some, but not too much bite. Too coarse an edge and the paper will tear, to polished and the blade will have trouble grabbing the very soft paper. It works best with an "upper medium" finish, which I have come to really like.
 
It is really easy to cut toilet paper laying on the table if blade is vertical adding some pressure to it. And if it is not quite vertical, how you make sure that this is not a case?

I know that free hanging toilet paper is hard to cut - will same knife with pass your test also cut free hanging toilet paper?

Thanks, Vassili.
 
Well the hole point of cutting on the bias is, that you keep the blade flat on the primary bladebevel. If you tilt the blade vertical somewhat it is not cutting "on the bias" anymore. This is why the paper has to have some volume to it. It is physically impossible to cut a piece of flat paper on the bias - obviously. This test is also kind of pointless with steep saber grinds. If you put the knife on the saber grind it will be angled too much, if you put it on the blade flat, the edge will be well above the cutting goods. The knife that cuts toilet paper on the bias well should be able cut free hanging paper towels in a draw (I have yet to see a blade that will pushcut paper towels). It will not necessarily cut the same fluffy toilet paper free hanging though.

But I repeat, this is NOT the most stringent test of sharpness. It offers no bragging rights. Hair whittling edges will pass this test easily (although, as you may notice, fully polished edges don't do as well as ones with a little bit of bite to them). But the issue "is a shaving edge sharp enough?" appears frequently and an edge that will cut toilet paper on the bias passes my personal test of functional sharpness. It is a good deal sharper than just shaving though.
 
Cutting hanging Paper towels is my personal sharpness test. I also tightly wrap up the piece that was cut off and slice it in half. An edge that does both cleanly is what I want for my edges.
 
You must log in or register to reply here.
Back
Top