How to make black peppercorns extremely fine? The black pepper I buy come in containers where you can grind it on use and they come out fine but not super fine.

I'm just wondering :


how do powder suppliers e.g. the companies which make curry powders etc make black pepper so fine?
What can I use to make my peppercorns more fine, it seems the store containers with grinder do just as good a job as a purpose bought pepper grinder(mill I think its called)?
How does a mortar and pestel compare to above?  I imagine the pepper is always much bigger?
Better grinding and sieving

If you think about it - spice powders are essentially flour. Pop it in a good blender. Blend, let it settle and sieve to required consistency. Repeat with oversized particles.

In an industrial setting this would likely mean a large mill and vibrating sieves, but you can, very carefully get the same results on a smaller scale. I believe some folks also use coffee mills for this, though obviously not one you have or intend to use for coffee.

For small quantities, you could probably use a spice mill or mill attachment on a blender. Just take your time. 

Its also worth remembering a pepper mill cracks not grinds pepper.