Digital BW, The Print

SPI?, that's a new one for me.

Jone Cone of Cone Editions has stated many times that he can see 
differences in a printed image up to 720PPI. Of course he has access 
to a drum scanner that can give him that resolution.

I remember Bill Berg also saying many times to size your images 
without resampling and let the PPI fall where it may. He sort of drew 
a line at 240PPI being the lowest desirable resolution for b&w quad 
printing.

BTW, I haven't heard of Bill Berg in a long time.
Cheers,
Andre