If you want to
print a photo book or if your book contains illustrations, drawings, which you
have to scan (scan), reading this article should save you time and sweat! These
lines are intended to teach you a little more than the common sense advice
given in the article "Insert images into a Word file ". You will
learn why it is important to choose a good scanning resolution. You will also
see how to determine the latter according to the work to be scanned. Even more,
you will discover the technical reasons which impose these choices. For the Document imaging this is important.
To print well, you must first scan well
Rather than
choosing a "wet finger" scanning resolution, it is better to know the
working resolution of your provider's press. The HP Indigo® presses used at DFS
+ use a line size of 175 lines. This means that over a distance of one inch
(2.54 cm), the press will print 175 lines of dots of different sizes.
Unless you are a
man of art, the concept of lineage must be foreign to you. However, you should
be familiar with the concept of resolution described in dots per inch (dpi).
There is a relationship between the line size and the point resolutions. Various
coefficients can be applied to switch from one to the other depending on the
quality of the document to be produced and the levels of linearity. However,
for simplicity, we consider that a coefficient of 1.5 is suitable for a press
that prints in 175 lines. So the "ideal" resolution to get the best
result on our presses is: 175 x 1.5 = 262.5 dots per inch.
To simplify,
scanning your images to their final format at a resolution of 300 dpi is
perfect for our presses. This is perfect for the Document imaging
services now.
Why don't you “oversample” your scans?
You may be
tempted to use working resolutions larger than 300 dpi when finalizing your
image. After all, 21st century hard drives aren't short on "gigas" to
easily store your documents. The result may however be opposite to the desired
effect.
