Type issues matter, because content is inseparable from its form. The "crystal goblet" theory argues that typography should transmit meaning as transparently and unobtrusively as possible; however, this presupposes a neutral perspective from which to communicate. It's possible—perhaps likely—that all perspectives on form are interested, and thus we as designers should take such decisions seriously.

Characteristics of letter forms

(See pg. 159 in Document Design for visual examples.)

• Strokes: the basic building blocks of alphanumeric glyphs (ex: lines, curves, and circles)
• Serifs: the "feet" or markings at the ends of vertical strokes in some font families
• Case: the distinction in many font families between uppercase (or capital) letters and lowercase letters
• Counters: an enclosed or mostly enclosed area in a letter (the stroke that encloses a counter is called a bowl)
• Stress: the orientation of counters in a font family, usually either vertical or oblique
• Baseline: the imaginary horizontal line upon which letters sit
• Descenders: the strokes on some letters, such as a lowercase y, that go under the baseline
• X-line: the imaginary horizontal line at the top of a lowercase letter x signifying the normal height of lowercase letters (called the x-height)
• Ascenders: the strokes on some letters, such as a lowercase h, that go above the x-line
• Cap-line: the imaginary horizontal line at the top of uppercase letters signifying their normal height (called the cap-height)

Typeface Categories

• Serif (with feet) vs. San Serif (without feet)
• Roman (regular) vs. Italic (slanted to the right)
• Text (designed for long-form reading) vs. Display (designed for rare emphasis)
• Monospace (all letters given the same width) vs. Proportional (letters given variable widths)

Features of Type

• Legibility: the extent to which individual letters are easily discernible
• Readability: a measurement of the text's ability to be easily and effectively skimmed, scanned, and read
• Usability: a measurement of a text's effectiveness at being used to accomplishing a specific task

Text Spacing

• Leading: the vertical distance between lines of text
• Kerning: the distance between individual letter pairs
• Tracking: the distance between all letters in a word

Digital Type

• PostScript, TrueType, and OpenType: digital font definition standards that stipulate how glyphs will appear in a variety of output modes (screens, printers, plotters, etc.)
• Unicode and ASCII: character code systems wherein glyphs are assigned code values
• Antialiasing: using pixels around glyphs to more smoothly integrate them into their backgrounds