Two things have significantly improved my sharpening, a black marker and a magnifier.

I sharpen many knives, probably 50 blades last week and I do not feel like I made a dent in my box of knives to sharpen.


Especially when I am creating a new profile (changing the angle), I like to mark both sides with a marker. This provides a very clear idea of where I am removing metal and makes it easier to see when I make it to the very edge. You can also feel for the edge that is created.


The next item has to do with a visual inspection. Especially when I am close to the edge, my old eyes can miss areas, so I like to use magnification.


I really like a 10X Loupe such as the Carson LumiLoupe 10X Power Stand Magnifier (LL-10), Black/Clear for $9.


https://www.amazon.com/gp/product/B000CAHCQS


I even have one with LED lights for $14 but I usually use the other 10X.


https://www.amazon.com/gp/product/B088D6PPLM


If you place a loupe magnifier on a piece of paper, it is in focus (or should be). This means that I directly set the loupe on blade when I look. You can also get an old school type for $7.


https://www.amazon.com/gp/product/B01HZUKF2A


When I want better magnification and pictures, I use a USB device. I think that most of them are about the same for about $25. I chose


Jiusion Original 40-1000X USB Microscope with Portable Carrying Case, Digital Magnification Endoscope Camera 8 LEDs Metal Base for Micro USB USB-C Android, Windows Mac Linux Chrome


Because it has both USB-A and USB-C, which means I can easily connect to my Linux computer and my Android Phone.


https://www.amazon.com/gp/product/B07DRGR6LX


I then spent another $22 on an adjustable stand


https://www.amazon.com/gp/product/B0797PPX8D


There are many choices.


I like to test my blades by slicing paper. I always use news print because it is fine and more difficult to slice than say printer paper. Paper has grain and it is easier to cut in one direction than the other.


This video shows 5 methods to test for the grain direction.


https://www.youtube.com/watch?v=cO_HAeH7pGw


I won’t bother posting images of edges off different sharpening medium, but you can see the difference in scratch patterns as well as wire edges. I can say that if you really want to see what a nice edge looks like, take a look at a Flex Cut tool with a factory edge.


That said, if people really want to see images of these things, I will generate some if I do not have them just sitting around.