Potato Vs. Corn Starch

[KBFlyer]

Just to reply, nothing wrong with the stones, but if you also use those stones for say knife sharpening or tool sharpening, weather they are natural or composite stones they will in time take on a wear pattern that is not exactly flat.

This is why a flat hard surface with Emery paper is best. This process will always be flat. The diamond stones will stay fairly flat but are limited in size. A full sheet of emery is a much better work surface.

Ya its not rocket science as to what is flat.

This one is used for knives

This one side of this stone is used for fishing hooks, Nail punches and the like.
Been used a lot.

And this side is perfectly flat

 

[SmokinEdge]

Ya its not rocket science as to what is flat.

This one is used for knives
View attachment 688516

This one side of this stone is used for fishing hooks, Nail punches and the like.
Been used a lot.
View attachment 688517

And this side is perfectly flat
View attachment 688518

Cool.