Printing
DS9 provides strong Postscript
printing support. This is not a screen capture method, but a full level
1 and level 2 postscript driver. The postscript images generated are detailed
and accurate as possible, given the resolution of the data, and the printing
resolution.
Postscript Level
Level 1-- The postscript generated consist
of a color lookup table and image data, encoded in ASCIIHEX.
All line graphics and text are postscript elements.
Level 2-- The postscript generated consist
of a color lookup table and image data, compressed with RLE, and encoded
in ASCIIHEX85.All line graphics
and text are postscript elements.
Postscript Color Model
DS9 supports three color models for level
2 postscript. All three color models generate approximately the same size
files.
RGB
CMYK
Grayscale
Resolution
Most printers dither to achieve various levels
of gray or color. So a 300 dpi printer's affective resolution may only
be 53 dpi after dithering. This is fine for analysis and proofs. On the
other hand, when generating images for publication, color separation is
used to achieve the full resolution of the printer . A 150 dpi CMYK image
will generate four 150 dpi images (one for each color). For example, ApJ
requests submissions be postscript level 2, CMYK, 300 dpi. In reality,
150 dpi is more than adequate. See Guidelines
for Authors Submitting Electronic Art Files In general, select
the lowest resolution possible, as postscript file size grows by
the square of the increase.
53 dpi-- use for 300 dpi printers
72 dpi-- use for 600 dpi printers
75 dpi-- use for 600 dpi printers
150 dpi-- use for publication
300 dpi-- use for publication
600 dpi-- use for publication