The Basics of Typeface Anatomy

Detail shot of wooden letterpress letters in print workshop.
Alys Tomlinson/Getty Images

Typeface anatomy refers to the individual features of particular characters in a font. Certain features are common to most characters and a few apply only one or two characters in a typeface.

Learning about serifs, strokes, counters and other parts that make up the letters in a typeface is not something of interest only to font fanatics and type designers. The shape and size of certain elements are usually consistent throughout any given typeface and can help you identify and categorize typefaces.

Although most font users don't need to know the difference between a spur and a beak or a tail and a leg, there are terms that most designers should be aware of. 

Strokes

Think about the strokes you make with a pen when printing letters and you'll have an idea what the broad meaning of stroke is for a font. Most letterforms are made up of several specific types of strokes:

  • A stem is the primary vertical stroke of a letter. There are two stems in an uppercase H.
  • A diagonal stroke is an angled stroke, such as you'd find in an uppercase A.
  • An arm is a horizontal stroke that only connected at one end. The three horizontal strokes on an uppercase E are called arms.
  • A crossbar is a horizontal connecting stroke that is connected at both ends, such as the horizontal stroke on the uppercase H.
  • A cross stroke is a horizontal stroke that is not connected at either end. Think of a lowercase t.
  • A counter is a closed space in a letter, such as the inside of an O.
  • A bowl is a curved stroke that encloses a counter.

Ascenders and Descenders

An ascender is a vertical stroke on a lowercase letter that is higher than the x-height of the character. In the term "x-height," the top part of the h is taller than the main body of the lower case letters, so that part of the letter is an ascender.

Descenders are parts of a letter that extend below the invisible baseline—the tail on a lowercase y or a g, for example.

The height of ascenders and descenders varies among fonts. The ascenders and descenders directly affect the amount of necessary leading, which is the vertical space between lines of type, measured from baseline of one line of type to the baseline of the next line.

Baseline

The baseline is an invisible line that each character sits on. The character may have a descender that goes beneath the baseline.

x-Height

The x-height of a font is the normal height of the lowercase letters. In most fonts, the letters o, a, i, s, e, m and other lowercase letters are the same height. This is called the x-height and it is a measurement that varies among fonts.

Serifs

Serifs are small decorative strokes usually found on the main vertical strokes. Serifs improve the readability of a font when it appears as a block of text. Probably the most familiar characteristic of typefaces, serifs come in several constructions including:

  • Hairline
  • Slab
  • Wedge

Serifs vary as much as the typefaces they adorn. Classifications include:

  • Modern
  • Old Style
  • Blackletter
  • Informal or Novelty

Not every font has serifs. Those fonts are called sans serif fonts.

The end of a stroke that doesn't have a serif is called a terminal.