I found this on the website of graphic designer Chris Glass, www.chrisglass.com
It's a useful reminder of the various parts of letterforms. It was adapted by Chris from Typographic Design: Form and Communication by Rob Carter, Ben Day and Philip Meggs. I also like what Chris has to say about communicating design.
Every profession has a language.
Here are some words common to a typographer. For the most part, these words never really come up in the daily grind of a designer. Design somehow exists on soft, subjective language that gets into feelings and moods. Who needs semantics when you can have "cool" or "pretty"?
This entry stems from a conversation with Marmot at a museum in German. We talked briefly about type. I felt all tongue tied. My ability to communicate what I had memorized in college was lost. So I brushed up on the terms.
Baseline: An imaginary line upon which the base of each capital letter rests.
Capline: An imaginary line that runs along the tops of the capital letters.
Meanline: An imaginary line that establishes the height of the body of lowercase letters.
X-height: The distance from the baseline to the meanline. Typically, this is the height of lowercase letters and is most easily measured on the lowercase x.
All characters align optically on the baseline. The bodyheights of lowercase characters align optically at the x-height, and the tops of capitals align optically along the capline. To achieve precise alignments, the typeface designer makes optical adjustments. (What does this mean? This means that characters with a curve like an o actually rest a little below the baseline and a little about the meanline to visually match letterforms with a defined edge.
Apex: The peak of the triangle of an uppercase A.
Arm: A projecting horizontal stroke that is unattached on one or both ends, as in the letters T and E.
Ascender: A stroke on a lowercase letter that rises above the meanline.
Bowl: A curved stroke enclosing the counterform of a letter. An exception is the bottom form of the lowercase roman g, which is called a loop.
Counter: The negative space that is fully or partially enclosed by a letterform.
Crossbar: The horizontal stroke connecting two sides of a letterform (as in e, A, and H) or bisecting the main stroke (as in f and t).
Descender: A stroke on a lowercase letterform that falls below the baseline.
Ear: A small stroke that projects from the upper right side of the bowl of the lowercase roman g.
Eye: The enclosed part of the lowercase e.
Fillet: The contoured edge that connects the serif and stem in bracketed serifs. (Bracketed serifs are connected to the main stroke by this curved edge; unbracketed serifs connect to the main stroke with an abrupt angle without this contoured transition.)
Hairline: The thinnest strokes within a typeface that has strokes of varying weights.
Leg: The lower diagonal stroke on the letter k.
Link: The stroke that connects the bowl and the loop of a lowercase roman g.
Loop: See bowl.
Serifs: Short strokes that extend from and at an angle to the upper and lower ends of the major strokes of a letterform.
Shoulder: A curved stroke of the letter S.
Spur: A projection - smaller than a serif - that reinforces the point at the end of a curved stroke, as in the letter G.
Stem: A major vertical or diagonal stroke in a letterform.
Stroke: Any of the linear elements within a letterform; originally, any mark or dash made by the movement of a pen or brush in writing.
Tail: A diagonal stroke or loop at the end of a letter, as in R or j.
Terminal: The end of any stroke that does not terminate with a serif.