This article is from the Lefthanders FAQ, by Barry D. Benowitz b.benowitz@telesciences.com with numerous contributions by others.
First, you must realize that (drinking) cups come in two varieties:
symmetric and not symmetric. Cups that are not symmetric may have
a lip to ease pouring the contents. If this kind of cup is right
handed, the lip will be on the side of the cup which is away from
the body, which allows for a easy neat motion. If this cup is
picked up with the left hand, the lip is toward the body, which
makes it awkward and messy to pour.
For symmetric cups, the problem is that when the decoration is only
on one side. When the right handed individual picks up a right
handed cup, he is able to see and enjoy the decoration. A leftie
using that cup presents the decoration to the world; he is unable
to see it.
Lefties would benefit with symmetric cups with designs on both sides;
cups with lips would have to be made in both right and left handed
varieties.
 
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