you dislike the black coating on your knife? you think its unhealthy?

>buy nail polish remover
>cover the blade with it
>scrape off the coating with a spatula

after this you could apply a nice patina.

>clean and degrease the blade
>apply mustard
>for forced patterns: use a needle, nail, brush or a small screwdriver and smear the mustard
>clean the blade after a few hours

you can improve the results with a combination from mustard and vinegar.

you want no patina pattern, just a black blade? but without coating?

>remove the coating
>mix up coffee powder with water
> let the knife rest a few hours in it (4-6h)

custom patinas and darkening will show the best results on non-stainless steel blades. your knife should be made from carbon steel (C60, C70, C75, 1095, O1)

post your results!