Digital BW, The Print

Lotusm50,
I think the problem that I described to start this thread is only
apparent when your chosen ppi is some simple fraction of 360ppi - as
is 300ppi.  When the ppi is some odd number like 327ppi or 941 ppi or
perhaps as suggested earlier in this thread 301ppi or 299ppi then the
maths involved in the driver resampling to the native printer
resolution (360 ppi / 720 ppi / ...) doesn't give rise to the 'jagged'
effects that I described.

So, I believe the answer to your question is "no".  You can print any
file at any ppi without the jaggies problem - as long as your file
isn't a simple fraction of 360ppi - like the 300ppi where I found my
problem.  You, like many people, may have never seen this problem, but
those who print 300ppi files should look carefully - you my find a
step improvement in your printing by the simple action of resampling
to 360ppi before printing.

Steve
http://www.virtuallygrey.co.uk/

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Lotusm50"
<LotusM50@s...> wrote:
> What I don't get is, does this mean that you can really optimally
> print only 4 or 5 different sized prints for a given file.  Say with a
> given file you can print an 8x10 print at 720 ppi.  Then say you want
> to crop it differently leaving the file smaller by 15%.  Does that
> mean you can't print the file at the 8x10 size because it would no
> longer print at 720 ppi (or 360 ppi)?  Or odes the printer dricer
> automatically re-size file sent ot the printer to the optimal
> resultion for the printer.  It would seem quite odd to me that a
> proffessional quality printer would be so limited in effective print
> sizes.  Or is the quality difference between printing at 360 ppi and
> 320 ppi in fact almost impossible to see?  I don't think I ever try to
> print at 360 or 720 ppi.  I take the file as it comes and if I want an
> 8x10 or an 11x14 I print it to that size (using 1160 with CIS &
> Piezotone inks).  I never really see any problems with the resolution,
> detail, or quality of the print.
> 
> What shouls I be noticing in a print not printed at a multiple of 720
> ppi that I am not seeing?
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Bob Frost"
> <bob@f...> wrote:
> > Steve,
> > 
> > I haven't printed at some of those resolutions, but I always
> understood that 
> > the numbers should be factors of 720ppi, the ppi that the printer
> uses for 
> > printing, not the dpi. So 360ppi is OK, as is 240 and 180, but not
> 480 or 
> > 576. Easy to confirm by printing a set of black and white 1 pixel
> lines and 
> > looking for the aliasing patterns. Many give you a lovely 'tartan'
like 
> > print (for those of you who know of Scotland).
> > 
> > Bob Frost.
> > 
> > 
> > ----- Original Message ----- 
> > From: "Steve Kale" <stevekale@b...>
> > 
> > 
> > I understood good practice to be at least always use a clean factor
> of the
> > print resolution ie 2880/4=720, 2880/5=576, 2880/6=480, 2880/8=360,
> > 2880/9=320, 2880/10=288.  The 300 simply came about as a result of
> the old
> > 2x150lpi (as Bob Frost noted in an earlier post).