On Mon, Jul 26, 2004 at 11:33:03PM -0700, Brooks Moses wrote: > At 11:15 PM 7/26/2004, you wrote: > >On Sat, Jul 24, 2004 at 03:21:39PM -0500, Bill McClain wrote: > > >> The printer > >> expects CMYK images (not RGB!) where the resolution is approx. 2 times > >> the screen count in the final print, @ the physical size on the paper. > >> So if you have an image in your PDF that is 10 cms /4 in. wide, and you > >> want it printed in a 150 lpi (lines per inch) screen, make sure the > >> original resolution is 300 dpi @ 10 cms / 4 in. > > > >Now that's interesting. I imagined you would get the best results with > >images that were designed exactly at the printer resolution. > > You might, but that would only be true if you also have the image aligned > exactly with the printer resolution -- which is unlikely to be the case > unless you do it explicitly. Having the 2x-or-higher resolution means that > the downsampling in the printing process will produce an acceptable result > no matter what the alignment is. > > Beyond that, I suspect there are also some effects involved in the fact > that the printer is creating a screen rather than dots of pure color; there > are things going on in the screen that are on a finer scale than the line > spacing, and having the higher-resolution to base them on probably produces > a better result. > > - Brooks
For a screened picture, you can often get away with less than twice the lpi, especially if there are no sharp transitions. On the other hand, pure black-and-white line drawings are best printed without screening. For such images, higher resolutions are better. 600dpi is enough for losing jaggies. Up to a point, more is better, but printer resolution (2400dpi or more) would produce very large bitmaps. -- Siep Kroonenberg _______________________________________________ ntg-context mailing list [EMAIL PROTECTED] http://www.ntg.nl/mailman/listinfo/ntg-context
