Simply put, the size of type is measured in points.
Points are part of the basic and essential language designers use to discuss typographic elements.
If you are a designer, you're probably already familiar with points.
Let's put it in another context and look at the relationship between inches and how many
points add up to one inch. Here is 1 inch. In every inch, there are six units called Picas.
In every pica, there are 12 points.
If you do the math, that means there are 72 points in an inch.
So points are tiny measurements that are about the width of a thin line.
Like most type terminology, the point system is based on the traditions of movable or physical type.
The point size was the height of the body of the piece of type.
The body height depended on the tallest Ascender and the lowest Descender in the font.
Within that height, the X-height of the font varied, which is mostly wide typefaces that
are the same point size, can look quite different.
Another measurement that affects the way type looks is more subtle and depends on the design of the font.
It is called the set-width.
For example, if you compare these 5 Es which are the same X-height, you can see that the widths differ.
Similarly, look at these Ms, their X-height is the same, but their set widths differ.
Set width affects how many characters will fit within a line of type.
A line of type is also measured in picas.
The width of a line of type is called the Measure of the line or the block of text.
For example, the Measure of this block of text is 30 picas wide.
Points are really tiny increments, but they can define the characteristics of a typeface.
These tiny increments create subtle differences between the height, width, and other proportions
of a typeface and they play a vital role in creating its unique appearance.
In the next video we are going to look at how other small increments define the proportions
of letters, as we explore typographic variations of width, weight, and slope.