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