Digital BW, The Print

I did a series of tests with my printer, a 1270 using the Epson
driver.  Short answer: 360 or 720ppi print noticablely better 
than any other resolutions.

Long answer:
I'm fairly picky.  I usually don't enlarge beyond 4-5x in the darkroom.
I look at prints from 6" away.

The _image_ resolutions I tested were: 840, 780, 720, 660, 600, 540,
480, 420, 360, 300, 240, 180ppi, 8-bit grayscale images printed from
Illustrator.  I created the different resolution versions by starting at 
840ppi, and downsampling to each successively lower resolution in 
Photoshop.  My test  image had some thin slightly diagonal lines 
(wood joints) which helped identify differences.  The thing that 
immediately stands out is moiring(?) in these lines at image resolutions
other than 360 or 720ppi. 420 and 300ppi, for example, look _way_ 
worse than 360ppi.  In other, more organic areas (rock texture), 
pixelation is  noticable at 240ppi, but not at 300ppi (naked eye).

As for the difference between 360 and 720ppi, I see no difference to
my naked eye, but under a 7x loupe, can see faint pixelation in certain
areas (sharp, diagonal lines) in the 360ppi file that are smooth in the 
720ppi one.

I'm guessing this information would apply to other Epson printers as
well, but you should probably test your own printer/driver combination.

Anyone else have experiences to support/contrast this?

BH 

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "nakalele2" 
<floydd001@h...> wrote:
> Could someone comment on the current state of mind 
> concerning the difference between printing at 360 dpi or 300? 
> I was under the impression that anything above 300 was going 
> above and beyond the call of duty.  One of my sources being
> John Caponigro's book "Adobe Photoshop Master Class", which 
> I realize is probably somewhat "aged" in the ever changing world 
> of digital prints.  thanks,  doug