Digital BW, The Print

For the particular printing I'm doing, I've had a number of people 
suggest that I select "error diffusion" for printing. 

The problem is most always these are people who don't have or use the 
Epson 2400, and I don't have a clue what "error diffusion" is or where 
I'd select it for printing. I don't think you can do it with the 2400. 

Please let me know if you can explain what it means and if you can 
select it with the 2400. 

Best, David