Digital BW, The Print

>> My question - Aren't all inkjet printers required
>> to use a dither by definition?
> 
> Not really.  Dithering is a process in which two or more pixels are assigned
> two or more different colors, with the expectation that the human eye will
> see the two pixels blend into some intermediate color that cannot be
> directly represented in a single pixel.

You are confusing pixel and dot here. Different dots, different inks are
combined to re-produce the pixel.

>For example, if you have only three
> possible colors for your pixels (in the world's cheapest inkjet printer,
> useful for hypotheses like this one), the only way to represent more than
> three colors is to dither and hope that the image will be viewed from far
> enough away that the dithered pixels will blend in the eye of the viewer,
> producing a perception of some intermediate color.

You don't need to be that far away, what ink jet printers have you been
using to see such output?  Even with a low end offset job, you see the
pattern arms length, but your brain still sees the colors that the screen
frequency and angles create with the four inks.

Carolyn