Page 7: Text Alignments
You're probably accustomed to working with text alignments. Until you have more training, stick to the guideline of using one text alignment on the page:
either all text is flush left, flush right, or centered.
This text is flush left. Some people call it quad left, or you can say it is left aligned.
This text is flush right. Some people call it quad right, or you can say it is right aligned.
This text is centered.
If you are going to
In this paragraph it is
difficult to tell if this text
was centered purposely
or perhaps accidentally.
The line lengths are not
the same, but they are not
really different. If you can't
instantly tell that the type
is centered, why bother?
This text is justified. Some people call it quad left and right, and some call it blocked - the text lines up on both sides. Whatever you call it, don't do it unless your line length is long enough to avoid awkward gaps between the words because the gaps are really annoying, don't you think?
Source: The Non-Designer's Design Book by Robin Williams