Figure 1. The PDF Presentation feature in Photoshop CS allows you to quickly create a slide show that’s handy for checking in with clients.
EPS (Encapsulated PostScript)
EPS is a format that encapsulates or wraps all artwork
(vector and bitmapped) in PostScript code; it
includes a low-resolution preview of the artwork for
display purposes. This format was designed to create
files that could be placed in page layout applications,
then left alone. EPS files are to be printed to a
PostScript printer or RIP (Raster Image Processor).
You can expect poor-quality EPS image output from
low-cost inkjet printers.
When you place an EPS file in an application,
it’s protected from any major changes to its
structure: You’re able to scale the artwork, but you
cannot down-sample the resolution, change the type
or colors in the art, or even crop correctly. To make
these changes, you’ll need to return to the originating
application (such as Photoshop or Illustrator). Or
you can save the file as a TIFF instead.
The low-res preview displays the artwork onscreen;
it’s used when printing to a non-PostScript
printer. You can choose between several previews,
from a very coarse 1-bit (black-and-white) preview to
an 8-bit TIFF preview. Using Photoshop on a Mac,
you can choose a JPEG preview, which creates a richcolored,
smooth preview and a smaller file size, too.
The EPS format offers lossy compression in
applications like Photoshop, which can result in
small file sizes. If you use spot colors, you can choose
a special flavor of EPS called the DCS (Desktop
Color Separation) format. Available in Photoshop, it
saves a file containing spot colors for accurate printing
from layout applications such as InDesign and
QuarkXPress. The EPS format also allows you to save
special halftone screens, useful for printing duotone
files. See Tip #2.
PDF (Portable Document Format)
The PDF is useful for saving artwork featuring precise
layout and a significant amount of formatted
text. Over the years, PDF has grown in stature from
its humble origins as a “precise file exchange” format
to a mainstay in the fields of prepress and electronic
learning. One benefit: PDF allows you to embed
fonts in a document, so type and layout both preview
and print consistently wherever the file travels.
PDF files are generally small in size, because of
the JPEG (lossy) compression. This makes them ideal
for e-mailing and web publishing. PDF supports
embedded ICC profiles and can display colors in the
document in a consistent fashion even at a remote
site on a calibrated, profiled monitor. This makes it
ideal for sending proofs to clients. See Tip #3 on how
to make PDF proofs that will dazzle your clients!
PDF documents will save layers in your artwork,
making it easy to return to applications such
as Photoshop and Illustrator to edit the artwork. The
neat thing about this is that the JPEG compression
degrades the PDF, but not the layered art—so you
can resave as PDF with JPEG compression, with
little loss to image quality. Some security measures
such as password protection and disabled printing
can be built into a PDF file, making it a good choice
for saving portfolio and client review art.