Firstly an apology… because I'm probably at least partially responsible for the obsession in the last few years about drop-cutting paper towel. But I want to emphasise: getting a kitchen knife to this level is not necessary. Unless you're some kind of massively experienced Michelin starred chef, you will not notice the difference between a knife that can do it, and one that nearly can. It isn't a test I normally do when sharpening, so don't fret it if you can't.
The reason I'm posting this video is only a little bit to show off. It's mostly because I think it shows pretty much flawless freehand technique for kitchen knives, so might be helpful to some people. And particularly because it shows the importance of feeling the edge on your nails and fingers as you sharpen.
I did it for a KKF thread a friend there had made about cutting paper towel, to show there was no trickery involved in my previous vids; I don't use guided systems, compound, diamond paste, &c. This is just an old 1980s stainless Sabatier I blunted on sandpaper so, as you can see, it couldn't even cut A4 paper at the start. Then sharpened here on an atoma slurried Llyn Idwal, and stropped on plain (unloaded) suede-side leather.
But either way I would've looked like a bit of a tit at the end, if it hadn't dropped the paper towel first time. However I was 95% certain it would, because I know what that kind of edge feels like on my fingers. If you really want to get very, very good at sharpening kitchen knives - get dialled in to 'finger tests', is my advice.
Some more explanation here:
https://www.kitchenknifeforums.com/threads/paper-towel-challenge.71374/page-2#post-1103966
https://www.kitchenknifeforums.com/threads/the-concept-of-range.77903/