Digital BW, The Print

Bob,

> Since the large Epsons use 360 ppi internally

What is a "large Epson", and what do you mean "internally"?  That would be a
property of the driver, not the printer.  And, at least for me, 360 would be
horrible!

> why shouldn't one say that
> sending 360 ppi is 'optimal'?

If it was perfect data, perhaps...but now you're in a "contest" with who
does better upsampling.  One thing that is, if the driver does upsample, it
has a particular algorithm that would take into consideration minimizing
artifacts with it's dithering algorithm...perhaps.

> It avoids the driver doing any upsampling of
> the image.

Only testing could decide which method is better.

> Sending them in
> most other ppi will be 'sub-optimal' in the sense that some pixels will be
> duplicated and some won't in the driver upsampling.

Only bad interpolation duplicated pixels...  I'd be hard pressed to believe
any of the interpolation methods used in the printer drivers or PS do any
pixel duplication.

> You may say that we won't be able to see the difference, but that is a
> different matter. Some may, and some may not. It might matter for
> some types
> of image and not for others.

Agreed,

Austin