Adobe 65023809 - Creative Suite 4 Master Collection Printing Manual page 69

• Binary: Produces a smaller file, but some page-layout applications as well as some
print spooling and network printing applications may not support images saved with
this option.
• JPEG: Compresses the file by discarding image data. Control the degree of JPEG
compression, from JPEG Maximum Quality (slight compression) to JPEG Low
Quality (aggressive compression). Files with JPEG encoding can be printed only on
Level 2 (or later) PostScript printers. Some devices do not support the printing of
separated output for files using JPEG compression.
Include Halftone Screen and Include Transfer Function: Maintains any custom screening
specification, as well as embedded curves meant to control the output values (for example, to
linearize output and compensate for device behavior). Many RIPs ignore these attributes.
Transparent Whites: Displays white areas in bitmap EPS files as transparent.
PostScript Color Management: Converts file data to the color space of the target device. Do
not select this option if you plan to place the image in another color-managed document. Only
PostScript Level 3 printers support PostScript Color Management for CMYK images. To print a
CMYK image using PostScript Color Management on a Level 2 printer, convert the image to Lab
mode before saving in EPS format.
Include Vector Data: Preserves vector graphics (including type). However, vector data in EPS
and DCS files is available only to other applications, and is rasterized if you reopen the file.
Image Interpolation: Applies anti-aliasing to the printed low-resolution image to improve out-
put when printing to devices such as laser printers.
Desktop Color Separations (DCS) 1.0/2.0
To facilitate the output of color separations, Quark®, Inc., developed the DCS format as a pre-
separated format with special features. It's a subset of the EPS specification. A DCS 1.0 image
actually consists of five files: four individual files (one each to represent cyan, magenta, yellow,
and black), and a "parent" file that references the individual color components. In the 1990s,
DCS files speeded desktop printing: only the parent file was sent to a desktop device. But in
separated output to high-end devices such as an imagesetter, the four high-resolution color files
were imaged for final output. Corruption or loss of any one of the five files constituting the image
would render the image unusable.
A later version, DCS 2.0, adds support for spot colors in addition to CMYK plates. The DCS 2.0
format also offers the option to save in a single-file format (Single File with Color Composite),
rather than requiring the user to keep track of multiple individual files.
When placed into InDesign or Illustrator documents, DCS files of either version are correctly
printed and exported, whether you choose separated or composite output; the constituent colors
are combined in the outgoing print or export. Non-Adobe applications usually require that you
generate separated output to correctly print DCS files.
The DCS format is also used for copy-dot images, which are created by scanning final film for ads
or articles when digital files of the materials are not available. Photoshop does not generate this
proprietary type of DCS file and usually cannot open or edit this file format without a special
plug-in. While InDesign can combine DCS files generated by Photoshop into correct composite
information during output, you may find that copy-dot DCS files require that you send separated
output from InDesign.
Joint Photographic Experts Group (JPEG)
While you may regard the JPEG format (file extension .jpg) as primarily for web use, a JPEG
with slight compression can be appropriate for print (provided the devices and processes in
your workflow accept JPEG images). The unattractive rectangular compression artifacts that are
frequently associated with JPEG images do not appear in images compressed with Maximum
quality settings in Photoshop.
That said, it's generally advisable to avoid editing JPEGs and resaving in the JPEG format because
each resave involves re-compression, and data can be lost unless the level of compression is
carefully chosen. It's best to save the file as a PSD or TIFF file, and then update InDesign or
Illustrator files to use the new image.
Adobe Creative Suite 4 Printing Guide 67