"vincent p. norris" wrote in message
...
My information is that in the old days, the thin periods and commas were
more delicate, and lasted longer if they were protected by the larger
quotes and parens.

That sounds reasonable, Jose, until you consider that whatever piece
of type comes last in the sentence, it is "protected" by the space
(is it called an M Quad?) that comes next. Each piece of type in the
line is "protected" by the pieces on each side of it.

A space cannot protect a printing character. The component being stressed
is the printing portion of the character, the part raised above (and
substantially smaller than) the main body of the type element. The point is
that during the printing process, each character of type experiences a force
against the printed surface, and for the more delicate characters (such as
periods and commas), this force would be unevenly distributed, putting a
slight lateral component to the force, when there is just a space on one
side.

Taken singly, this force is slight and seemingly inconsequential. But keep
whacking the plate over and over again, and eventually it's going to cause
the character portion of the type element to fail prematurely. According to
the theory that Jose is describing, by placing the more delicate characters
between two printing characters, the lateral force is reduced or even
eliminated, "protecting" the more delicate character.

One possible flaw in the reasoning is that type elements are not just simple
extrusions of the character itself. Most of the time, the character surface
is at the top of a sloped raised area on the type element. So a period,
even if it's just 1mm across where it prints, may actually have a 5mm (for
example, or even larger) base. One would think that would provide extra
strength, helping protect against damage.

However, I don't think that's necessarily an actual flaw in the reasoning,
as all of the type elements have such sloped sides, and the smaller printing
characters will still have less material than the larger ones, and may still
benefit from protection.

In any case, whether or not the theory that Jose related is correct, the
theory isn't talking about the main rectangular body of the type element,
and so just because there's a spacing type element next to a trailing
period, comma, whatever doesn't in any way serve to offer the protection
that the theory describes. If anything, the empty space is precisely what
causes the problem the theory describes.

Pete