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