Digital BW, The Print

What I usually do is simply send my files to QTR at whatever PPI they
already are rather than re-sampling.   In general I have files that are
between 360 and 720.  In the PC version what happens is the PPI of
the input is upsampled to 1440x720ppi using a bi-linear algorithm.  For
inputs of at least 360ppi I expect this upsampling is good enough.
Anything less should be upsampled using a better algorithm like
bi-cubic or what Qimage does.

Given all that if you are using Qimage probably the best would be to
feed QTR a file of 720ppi rather than 360 but whether you'll see the
difference is probably image dependent and how close you look at it.

Roy

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "ferdinand_paris" 
<ferdinand_paris@y...> wrote:
> 
> Roy, apropos of the exchange below, what DPI should we be using when
> sending an image to QTR for printing on the Epson 2100?  720 or 360?
> 
> I'm using Qimage on a PC to send the image to QTR via QTRGui, although
> this doesn't really matter.  UC inks and both matte and
> pearl/semi-gloss papers.
> 
> F_P
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Ernst Dinkla
> <E.Dinkla@c...> wrote:
> > >>Can you explain why you output from Qimage at 360dpi? My 
> > >>understanding (probably faulty :-) is that Qimage would output
> > >>the image to an Epson printer at 720dpi.
> > > 
> > > Because I read somewhere (I forget where) that this was as much as
> > > was necessary.
> > 
> > It depends on your printer. printer setting etc what native input 
> > the Epson driver expects in the input file. Qimage shows that 
> > native resolution above the preview to the right. For Epsons it 
> > varies between 360 and 720 PPI input.
> > 
> > What QTR will need per printer/paper/resolution/etc setting I 
> > don't know but one could ask Roy Harrington.  I doubt that there 
> > will be much difference between sending it 360 and 720 PPI from 
> > Qimage. If Roy doesn't provide you the answer you could check the 
> > Gimp-print sources.
> > 
> > You could try the test image from:
> > 
> > http://www.ddisoftware.com/qimage/quality/
> > 
> > but I have no idea whether that will work for the B&W workflow.
> > 
> > Ernst