Fast finish on a knife.

I decided to learn to sharpen properly, and I think of using the technique Korin_Mari said - creating and edge and crushing it, rinse, repeat. Because I still wobble a lot the knife is in terrible visual shape.

Is there a fast finish that could be restored so i could see where the new bevels (and scratches) are - painting the whole side of the knife with sharpie comes to mind. But I prefer not to.

if you're practicing on a cheap carbon steel knife, a light etch in ferric chloride would turn the blade dark in a few seconds. Just have to neutralize it afterwords.

Carbonext will be my practice knife. It is not very reactive. But that is a extremely good idea.

Can it possibly take more than 10-15 seconds per side to Sharpie a bevel? Also, comparing the reactivity of my Ichi TKC to my Watanabe, I'm not sure Ferric acid and the CarboNext is going to be your answer. FWIW - I've been freehand sharpening for 10 + years, I still wobble some, and the best cure is slowing down

The problem is that there are some very polished areas on the face of the knife, where I have applied too much pressure at too low angle, too high on the bevel. As if having faux bevel above the secondary bevel (IIRC the one that forms the edge was secondary, newbie on knives). So I need to restore is to some form of matte finish.

Medium sandpaper, P400, or coarse (brown) ScotchBrite, both along the edge