The attraction value of gray tones particularly affects the
consideration of blocks of type which vary in depth of tone according to
the blackness of the type face, closeness of spacing, etc.

Since the "seesaw" must have its sawhorse and the weighing scale its
point of support, it follows that any condition of equilibrium, physical
or optical, demands a point of balance. In design, this point will
determine the location of the related masses. It will be apparent upon
further thought that the point of balance should have some relationship
to the edge or confines of the design.

The confining edge of the design is usually a rectangle, on the printed
page. The location of a point of balance within this rectangle tends to
divide it. How shall it be divided in the most interesting way? By
applying the ratio of good proportion. So the point of balance may be
located usually on a line which divides the page into parts of 2 and 3.

When equal masses are to be balanced it is obvious that they will be
equidistant from the point of balance. (Fig. 12.)

[Illustration: Fig. 12. Equal masses balanced at equal distance from the
center point.]

When the masses are unequal the point is at unequal distances from the
centers of the masses. These unequal distances have the same ratio as
the masses themselves, but the larger mass is always the shorter
distance from the point. If 1 pound is to balance 4 pounds it is
obvious that the 1-pound mass must be 4 times as far from the point of
balance as the 4-pound mass.

[Illustration: Fig. 13. Mass of 4 units balanced by 1 unit.]

Hence, to balance two masses in a rectangle, the point of balance will
be found by proportion, placing it on a line which divides the
rectangle into parts of 2 to 3. The balancing of the masses across this
point will then be a matter of determining their relative distances from
it. It is apparent that the larger of two masses may be far enough from
the point of balance so that it will force the smaller entirely out of
the rectangle. It is of course easy to move the larger closer to the
point which automatically brings in the smaller. What constitutes a
proper distance from the edge of the rectangle will be discussed under
"Margins," in the book on Typographical Design.

[Illustration: Fig. 14. Mass of 3 units balanced by mass of 1 unit,
taking the point of balance upon the line which divides the space in
good proportion.]

[Illustration: Fig. 15.