fonts

typography

• Aperture

  The partly enclosed opening in a letter, such as the gap where the two terminals of a c stop or the mouth at the bottom of an e.

• Ascender

  The part of a lowercase letter such as b, d, or h that rises above the x-height.

• Baseline

  The invisible line that most letters sit on, and the line every other vertical type metric is measured from.

• Cap height

  The height of a capital letter measured from the baseline, and the edge designers usually mean when they say text should line up flush.

• Color font

  A font whose glyphs carry their own colors, gradients, or layers, with a palette the page can override rather than a single ink.

• Contextual alternates

  Substitute letterforms a font swaps in automatically based on the neighbouring characters, so joins and repeats look natural.

• Counter

  The fully enclosed white space inside a letterform, the ring of an o or the bowl of a b: letter anatomy, not a character count or a CSS counter.

• Descender

  The part of a letter such as g, j, p, or y that drops below the baseline.

• Fallback font

  The typeface actually used when the preferred one is missing or has not loaded, either for the whole run of text or for characters it lacks.

• Faux bold

  A bold or italic the browser fakes by smearing or shearing the regular weight, because the real style was never loaded.

• FOFT

  A loading strategy that shows the roman weight as soon as it arrives and lets the remaining styles swap in afterwards, so the swap happens in stages.

• FOIT

  The blank period when a browser hides text entirely rather than show it in a fallback face while the web font loads.

• Font metric override

  Reshaping a fallback font's size and vertical metrics in CSS so it occupies the same space as the web font and the swap shifts nothing.

• Font pairing

  Choosing two or more typefaces that work together, usually one expressive and one neutral, with enough contrast to read as a deliberate choice.

• Font smoothing

  How a device softens the edges of letterforms, either by shading whole pixels grey or by lighting a pixel's colored subpixels separately.

• Font stack

  The ordered list of typefaces a rule names, each tried in turn until one is available, ending in a generic family.

• Font subsetting

  Shipping only the characters a page actually needs, cutting the font file down and letting the browser fetch ranges on demand.

• Font weight

  How thick a typeface's strokes are, named in steps from thin to black and numbered from 100 to 900 on the web.

• FOUT

  The visible swap when a page first paints text in a fallback face and then re-renders it once the web font arrives.

• Glyph

  A single drawn shape in a font, which may be one character, a variant of one, or several characters fused together.

• Grade

  A variable font axis that thickens or thins strokes without changing any character's width, so text can get darker without reflowing.

• Hinting

  Instructions inside a font that nudge its outlines onto the pixel grid at small sizes so stems stay crisp and even.

• Icon font

  A font whose glyphs are icons rather than letters, addressed by code point or by a ligature so an icon can be styled like text.

• Ink trap

  A notch cut out of a letter's inside corners so spreading ink or blurring pixels do not fill the joint solid.

• Italic

  A companion style with letterforms redrawn on a cursive model, not merely slanted, used for emphasis and titles.

• Kerning

  The adjustment of space between two particular letters so the pair reads evenly.

• Legibility

  How easily one letter can be told apart from another, a property of the typeface's drawing rather than of how the text is set.

• Ligature

  A single glyph that replaces two or more letters whose shapes would otherwise collide, such as the f and i pair.

• Lining figures

  Numerals all drawn to cap height so they line up evenly with capitals and with each other.

• Monospace

  A typeface in which every character occupies the same horizontal width, so characters stack into columns down the page.

• Named instance

  A specific point in a variable font's design space that the designer has given a style name, so it can be picked like an ordinary weight.

• Oblique

  An upright typeface slanted to the right without redrawing its letters, which is why it lacks the cursive forms a true italic has.

• Oldstyle figures

  Numerals with varying heights, some rising and some dropping below the baseline, so numbers blend into lowercase running text.

• OpenType features

  Optional glyph substitutions and spacing rules packed inside a font file, addressed by four-letter tags and switched on from CSS.

• Optical kerning

  Letting software space letter pairs by looking at their shapes, instead of using the pair values the type designer built into the font.

• Optical size

  A font adjusting its own drawing for the size it is set at, thickening strokes and opening spacing for small text and refining both for large.

• Pangram

  A sentence that uses every letter of the alphabet at least once, used to show a whole character set in one line.

• Petite caps

  Capitals drawn to exactly x-height, shorter than small caps, so they sit flush with the lowercase around them.

• Point size

  The nominal size of type, measured in points, which describes the body the letters are drawn on rather than the height of any letter.

• Sans-serif

  A typeface drawn without finishing strokes on the ends of its stems, which is the default register of most interface type.

• Serif

  The small finishing stroke at the end of a letter's stem, and by extension the class of typefaces that have them.

• Signed distance field

  A texture storing each pixel's distance to a shape's edge rather than its color, so glyphs and icons rendered from it stay crisp at any scale on the GPU.

• Small caps

  Capital letters drawn at roughly lowercase height, with weight adjusted to match, so an abbreviation does not shout inside running text.

• Stylistic set

  A numbered bundle of alternate glyphs inside a font, switched on as a group to change the look of certain letters.

• Superfamily

  A type system whose serif, sans, and sometimes mono members share one skeleton, so they pair by construction rather than by taste.

• Superscript

  Small raised characters used for footnote markers, ordinals, and exponents, ideally drawn by the font rather than shrunk by software.

• Swash

  A letter drawn with an ornamental flourish, usually an extended entry or exit stroke on an italic capital.

• System font

  The typeface the operating system uses for its own interface, requested by keyword so each platform supplies its native face.

• Tabular figures

  Numerals drawn to identical widths so digits stack into columns, and so a changing number does not shift the text around it.

• Tittle

  The dot above a lowercase i or j.

• Tofu

  The empty rectangle a font renders when it has no glyph for a character, named for the block of bean curd it resembles.

• Tracking

  The uniform space added to or removed from every letter across a run of text.

• Type scale

  The fixed set of text sizes a design allows, chosen so sizes relate to each other rather than being picked one at a time.

• Type specimen

  A display of a typeface's characters, sizes, and styles made to show what the face can do rather than to communicate the text itself.

• Typeface

  The designed set of letterforms itself, as distinct from a font, which is one particular file or instance you actually use.

• Typography token

  A named bundle of type values (family, size, weight, line height, tracking) that a design system hands out instead of raw numbers.

• Variable font

  One font file that contains a continuous design space, so any weight, width, or other axis value between the extremes can be requested.

• Variation axis

  One dimension a variable font can move along, named by a four-letter tag: lowercase for the five registered axes, uppercase for custom ones.

• Web font

  A font file downloaded by the page rather than taken from the reader's device, declared in CSS and delivered like any other asset.

• X-height

  The height of a lowercase x in a typeface, measured from the baseline, which is what makes two fonts at the same point size look different sizes.