Adobe Photoshop CS4 - Manual (Page 460)

453 USING PHOTOSHOP CS4
Saving and exporting images
Last updated 1/10/2010
Smallest File Size Creates PDF files for displaying on the web, an intranet, or for email distribution. This set of options
uses compression, downsampling, and a relatively low image resolution. It converts all colors to sRGB and embeds
fonts. It also optimizes files for byte serving.
These PDF files can be opened in Acrobat 5.0 and Acrobat Reader 5.0 and later.
Standard (Acrobat only) Creates PDF files to be printed to desktop printers or digital copiers, published on a CD, or
sent to a client as a publishing proof. This set of options uses compression and downsampling to keep the file size
down, but also embeds subsets of all (allowed) fonts used in the file, converts all colors to sRGB, and prints to a medium
resolution. Note that Windows font subsets are not embedded by default. PDF files created with this settings file can
be opened in Acrobat 5.0 and Acrobat Reader 5.0 and later.
For more information about shared PDF settings for Creative Suite components, see the PDF Integration Guide on
the Creative Suite DVD.
About PDF/X and PDF/A standards
PDF/X and PDF/A standards are defined by the International Organization for Standardization (ISO). PDF/X
standards apply to graphic content exchange; PDF/A standards apply to long-term archiving of electronic documents.
During PDF conversion, the file that is being processed is checked against the specified standard. If the PDF will not
meet the selected ISO standard, a message appears, asking you to choose between canceling the conversion or going
ahead with the creation of a noncompliant file.
The most widely used standards for a print publishing workflow are several PDF/X formats: PDF/X-1a, PDF/X-3, and
(in 2007) PDF/X-4. The most widely used standards for PDF archiving are PDF/A-1a, and PDF/A-1b (for less
stringent requirements).
Note: For more information on PDF/X and PDF/A, see the ISO website and the Adobe website .
PDF compatibility levels
When you create PDFs, you need to decide which PDF version to use. You can change the PDF version by switching
to a different preset or choosing a compatibility option when you save as PDF or edit a PDF preset.
Generally speaking, unless there’s a specific need for backward compatibility, you should use the most recent version
(in this case version 1.7). The latest version will include all the newest features and functionality. However, if you’re
creating documents that will be distributed widely, consider choosing Acrobat 5 (PDF 1.4) or Acrobat 6 (PDF 1.5) to
ensure that all users can view and print the document.
The following table compares some of the functionality in PDFs created using the different compatibility settings.