Epson ES-800C, User Manual

Page: 35 / 89

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 3-8 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).
Resolution guidelines
This table shows the recommended resolutions in dots per inch
or pixels per inch for the image types and printing methods just
described. Also, you may want to experiment with your
scanner settings, possibly using a cropped version of your
image to save time, until you achieve the desired results.
Resolution guidelines
Line art
Black and 300-400
white printer
Electronic 300-400
color printer
Gray
scale Color
75 75
150-200 150-200
Printing press/
Imagesetter
400-800 150-200 150-200
Tip: Here’s how to calculate more precisely the required resolution
for gray scale or color on an electronic color printer or a
printing press:
1. Find out the lines per inch of the printing method. This is
the measurement of resolution for high quality image
printing. Do not confuse it with dots per inch, which is not
an equivalent measurement.
3-10 Scanner Basics