How do you test for dullness?

[Bighaze51]

I jus touch the edge on my arm hair. No need to shave bald patches ( the wife gives me a hard time for that) if it catches, it's close enough. When it doesn't do that anymore or I notice it ripping tape instead of cutting it, a couple swipes on the fine sharpmaker rods brings it right back to stupid sharp

 

[bdmicarta]

I rub the pad of my thumb lightly across the edge and feel for it to bite into the skin. If available I will try to slice some of the shiny thin advertising paper from the sunday newspaper. If the edge is sharp enough to bite into the edge of the paper then I know it is sharp.

If this is a knife that I am using, I don't require it to be sharp enough to cut the thin paper. If it still feels sharp then it is sharp enough for my EDC use. I suspect if it would cut copier paper then that is good enough for normal use. When it starts to feel really dull to my thumb then I make a mental note to resharpen it.

 

[Shotgun]

I feel the edge with my fingertips.
Started doing that as a butcher when younger, and have done it that way since.
I lightly push into the edge from side and pull back and very, very slightly downward.
If it catches skin its sharp, and after a while you can tell how sharp by how it catches.

I've tried various methods over the years and I've come back to this.

 

[average gimp]

I don't use paper or shaving - I put the edge at roughly a 20 degree angle on my thumb nail - if it bites in I'm happy. If it slides at all its time to sharpen (for me anyway)
How about you guys?

That's how I was taught and it works for me.

 

[link2derek]

I prefer to test for sharpness - different mindset, I guess.

 

[Doug C]

How easily or not it slices paper.
Different knives, different sharp.

DC

 

[herisson]

Tomato skin is a good reference in my book. If a knife slices a tomato without catching or dragging, that's a pretty sharp knife. Shaving arm hair and slicing (not shredding...) cash bills or those shiny catalog pages is pretty nice, also.