Epson ES-600C, User Manual

Page: 37 / 90

Printing presses are for high quality and high volume work.
You scan and edit your images and then send the files to a
service bureau or printing company, which uses high
resolution phototypesetters (also called imagesetters) like
the Linotronic
TM
300 for high quality text and gray-scale
images. For full-color images, you scan in color and then
use your image editing software to manipulate the image
and produce color separation files. If you plan to do this, see
the guidelines below on resolution and then follow the
instructions in your software manual for making
separations. Your service bureau or printing company
should also provide helpful information.
File size
In gray scale and color, use the lowest resolution that gives
acceptable quality for your printing method because high
resolutions mean large files. A letter-size full-color scan uses as
much as 25 megabytes (MB) of disk space.
Large files use up your computer and hard disk memory; they
take longer to process, to print, or to transmit by modem; and
they are more difficult to save to a disk for sending to a service
bureau or printing company.
Many printing methods cannot use all of the information stored
in a high-resolution scan, so in these cases part of the
information is wasted.
For example, the file size of the image on page 3-7 is only 40K
because it was scanned in gray scale at 75 dpi. Scanning the
same image at 300 dpi in gray scale would require a file size of
660K, and 24-bit color at 300 dpi would require 1900K (nearly
2 megabytes).
3-8 Scanner Basics