I totally agree. Hair is actually a lot easier to cut and, therefore, less dulling. The same applies to a razor. Woe unto the person who uses my (beard) razor to shave his/her legs.
But, to get back to basics, the original question was (paraphrased), “Of all things you can cut with a knife, does cutting paper dull them significantly more than the others?” I maintain that the answer is, “No.”
Conversely the internet suggests cutting sandpaper as the prime way to sharpen scissors.
Never sharpened scissors personally, so no idea…
Yeah, i got off track talking about scissors. I also have extensive experience with knives, having spent nearly 20 years in kitchens before an abrupt career change.
Good kitchen knives are also honed to be razor sharp. When you spend several hours a day cutting things, having a sharp knife makes a huge difference on the wear on your wrist. Using the cheap house knifes was probably going to give me arthritis or carpal tunnel, so I got some wusthofs instead. (You can also create a better presentation with sharp knives, allowing thinner and more accurate cuts.)
Foods like meats, fruits, and the “vegetables” that are actually fruits usually contain very little in the way of hard minerals, though actual vegetables (the plant parts of a plant) contain cellulose and other fibrous material that can do a bit more dulling on the blade, but still not that much.
Cutting other things, like paper, that has hard minerals in it will dull the blade much faster than meats or fruits.
Now, I am sure there are other things you could try to cut that would dull the knife faster, but if the question is simply, will cutting paper dull a knife faster than meats and fruits (and cheese for that matter), then I am pretty sure the answer is “yes”.
Yeah, scissors with a beveled edge that just needs to be put back into hone will find improved cutting after cutting through sandpaper.
That is because the sandpaper will remove and burrs or other blemishes along the blade.
You would get better improvement from properly honing them, and that technique would utterly destroy good scissors.
Re my notes and the notes of others here are certain scenarios where scissors have to be their sharpest to work properly (hair, fine textiles etc) and even a minute step off that level yields unusable scissors other scenarios like cutting copy paper in my example you can keep using “sharp enough” scissors very satisfactorily for years.
If you use a pair of “must be sharpest” scissors for paper cutting they will rapidly degrade to “sharp enough for stiff paper” which is useless for hair cutting here the scissor needs to glide through hair very quickly.
The answer is that soft materials can erode hard materials. We know that flowing water can erode rock, so why is it a surprise that paper can erode steel?
It doesn’t take much to dull a knife. The edge of a sharp knife is very fine—it’s actually the fineness that makes it sharp. Because of this, you don’t have to remove much metal to turn a sharp knife into a dull one.
Another thing that causes knives to go dull is for the edge to roll over (rather than for it to be eroded away). This is why steeling a knife keeps it sharp: the steel straightens up the edge. Again, since the edge of a sharp knife is so fine, it doesn’t take much to distort it. The material being cut doesn’t have to be harder than steel for it to roll the edge over.
I’ll mess with your minds:
How is a “sharpening” “steel” used?
The steel is that rod you see fine chefs use on a knife just before using it.
Different blade designs are used, depending on intended use.
I have a pair Barber’s shears (not “scissors”). The instructions with them were quite specific:
“Never use these shears for anything but human hair”.
The chef’s knives do not dull in the same manner as an axe or common scissors - the edge folds over - the steel is used to push the edge back in place. Using the steel as a sharpening stone will ruin the blade pretty much instantly.
Ever see a sign stating “We sharpen knives”? No sharpening stone for them.
I have both a guillotine type paper cutter and a rolling paper trimmer.
Paper is a special case. I’m guessing the way the fibers will stretch instead of simply shearing into two.
Amusing story there, now we know how you got your shawnee name runs with scissors
I’ve tried arguing exactly that point here before to no avail. It seems to be the overwhelmingly popular view that if you have two different materials of different hardnesses in contact, the softer one experiences all the wear, and the harder one experiences none at all. (And that the wear exerted by wood upon hardened saw blades is the result of contamination by hard mineral particles - likewise water upon rock, or chemical reaction or process).
But it seems entirely reasonable to me that the differential hardness means there should be differential distribution of wear, not just all of the wear falling on the softer material.
You’re saying the clay doesn’t help dull the edge? Well it does, along with the paper fiber itself. Do you know what plant fiber is made of? Calcium carbonate, calcium oxide, sometimes a little silica (the ash part after burning.) That will definitely dull steel. And it takes only a little cross-contract with the cutting edge to dull it. The real cutting happens on the first .005 millimeters of the cutting edge. The rest is just side friction.
As to our mothers’ insistence that paper will dull scissors faster than cloth, it’s probably not true (my opinion) as they’re made of roughly the same substance minus the clay coat. It’s constancy of use. A housewife doesn’t really cut cloth all day, unless she makes dresses as a business. In which case the scissors will really get dull.
I’m into knives so I kinda know how to sharpen scissors. The old rules no longer apply in our house.
Most scissors don’t have knife blades.
Professionals (including printers) sharpen their knifes as required.
And,
Your mothers scissors were probably a lot softer than a paper knife.
Also, scissors will work reasonably well even when not sharp, on many materials, simply by shearing rather than cutting. Scissors don’t work (or don’t work entirely) by simply being two sharp knives working from opposite sides. They work in part by forcing the material in two different directions ie placing it in shear.
Indeed - and in that respect, they function best when the mating faces are a close fit (i.e. either nice and flat, or non-flat, but precisely matching.
As long as they shear against each other throughout the length, they will cut. Explains why pruning shears are often bent. It makes shearing more continuous. Straight blades tend to diverge from each other.
Also, whether for scissors, knives, or shears, material that’s softer than the blade steel also causes dullness because they tend to coat or wrap around the very edge of the blade. Relatively easy to fix through a light touch-up by someone who knows blades.
Great discussion, but I’ll make this my last post to the thread.
IMHO, it is a myth that cutting paper dulls a knife blade significantly more than cutting string, rope, or many other materials. Obviously, cutting anything that is harder is going to dull a blade faster than cutting something that is softer. But paper does not have some magical blade-defeating powers that will ruin your knife the second they touch. Paper is just “stuff,” and cutting “stuff” dulls knives. When I cut paper using a ruler and my knife, the surface I’m cutting ON has a lot more effect than the paper itself.
In my experience, many people are told that cutting paper will dull a knife (or a pair of scissors) excessively and so “rules” are put in place to prevent it. Whether they are justifiable rules or not is up for discussion. In my experience working as an electrician who cuts up insulation, copper wire, cardboard, paper, tape, cloth, rope, string, sheetrock, and wood with my Kershaw, cutting paper is the least of my worries.
I’d guess this started from the concept of “Don’t use my knife/scissors that I only cut hair/cloth/meat/whatever with to cut anything else”, and the anything else was usually paper.
Flowing water erodes rock as it contains sand, etc- of harder rock.
Or dissolves the rock. Or erodes it through impact, like with falling rain or waterfalls, or splashing, and through pressure to some degree. But without carrying other substances it is a very slow process. The materials carried by water that erode don’t have to be harder than the rock to erode it, but a lot of it will be. Quartz and aluminum oxides are very hard and abundant, and fragile as well so likely to be broken into fine material carried by water.
What do you think it being cut when someone shaves their legs??