Digital BW, The Print

>...what is the sweet spot for file dpi to
>output for BW to a 4-color printer . . what are people using. ...

I scan at 4000 dpi and just leave it there.  It ends up above 360 and less
than 720.

I've done tests and found that the driver can use information above 360.  I
think I've read 720 is the limit.  As a practical matter, however, the
difference between 360 and 720 is barely detectable -- with either Epson or
Cone drivers.  The highest resolution (optical line pairs per mm) I've ever
seen with them is about 9 lp/mm.  At 360 you can hit about 7 lp/mm with
both.

Above 5 lp/mm the main visual difference in any system is probably edge
acutance, which can't really be measured by my lp/mm testing.  When viewing
actual enlargements and weighing file size, I concluded that 360 was the
highest I needed.

Paul
http://www.PaulRoark.com