How do you know if you are weilding a razor sharp knife or merely a kinda sharp knife?
There are a few techniques to test how sharp a knife is, some more dangerous than others.
The first technique is cutting paper. to start off with you hold a sheet of paper in front of you and use your knife to cut the paper in a downwards motion. Only a little bit of effort should be needed and if you knife cuts the paper cleanly then it is an indication that your is quite sharp. If on the other hand the paper merely crumbles or tears then it will take a bit more sharpening to get a razor sharp knife.
The second technique is running the blade along your thumb nail. "But isn't this going to cut off my thumb?" some of you may be thinking. It will not cut off your thumb because you only have to apply a very small amount of pressure to test your knife. To start off with you have your thumb at a near vertical angle and then put the edge of the blade at about 90 degrees from your thumb nail. You then slowly run the entire length of the blade very lightly accross your thumb nail and it will grip onto your thumb without sliding off if your knife is relatively sharp. If on the other hand your knife slips off then this indicates that your knife is a bit dull. This technique is also handy to determine if only a part of your blade is dull as the dull section will slip while the rest of the blade won't.
The last technique to tell if you have a razor sharp knife is to actually test if it will shave the hair off your arm or leg. Care must be taken when using this technique as there is the chance that you could potentially cut yourself. If you are careful and use some common sense then you should not cut yourself. This is the true test of a razor sharp knife and it is quite fulfilling knowing that you have got the edge to a point where it will shave you. To do this you hold the knife at a relatively flat angle and then just push it along either your arm or your leg. A dull knife wont cut the hairs, instead it will just push them over. On the other hand a razor sharp knife will have no trouble cutting the hairs and if you do it too much you will find that you have patches from where you couldn't resist testing your knife.
While not everyone will need their knife to be razor sharp, there are tasks where there is a huge benefit in having a razor sharp knife. Depending on what you use your knife for will determine how sharp you will need it. Hopefully this guide will have shown you a few techniques to tell how sharp your knife is. Take the time to maintain your knives edge and give it a touch up when it starts getting dull. One thing to remember is that a dull knife is a dangerous knife.