Typography Converter

The term 'em' originally referred to the width of the capital letter 'M' in a given typeface and point size, as 'M' was often cast on a square metal body or 'em-quad'. While no longer strictly tied to the 'M', an em unit in CSS is relative to the font-size of the element itself (or its parent for some properties).

Leading (pronounced 'ledding') refers to the vertical space between lines of text. It was originally named after the strips of lead used to separate lines of type in manual printing presses.

A pica pole, or type gauge, is a ruler traditionally used by typesetters and graphic designers, marked in picas and points, as well as inches or centimeters. It helps measure type size, leading, and column widths for print layouts.

The cicero is a unit of typographic measure used in some European countries. It is similar to the pica but based on a slightly different point size (the Didot point). One cicero is equal to 12 Didot points.

Kerning is the process of adjusting the spacing between individual characters in a font to achieve a visually pleasing result. For example, the space between an 'A' and a 'V' is often reduced.

In the early days of the web, designers were limited to a small set of 'web-safe' fonts (like Arial, Times New Roman, and Georgia) that were pre-installed on most computers. Today, web fonts allow designers to use a much wider variety of typefaces.

Variable fonts are a recent evolution of font technology that allows multiple variations of a typeface (like different weights and widths) to be stored in a single font file, offering greater design flexibility with smaller file sizes.

The x-height of a typeface is the height of its lowercase letters like 'x', 'a', and 'o'. A larger x-height relative to the capital letter height can make a font appear more legible at small sizes.

These terms come from the physical cases used by traditional typesetters. The capital letters were stored in the upper case, and the small letters were stored in the lower case, making them easy to grab.

An 'agate' is a unit of typographical measure used by newspapers for classified advertising. One agate line is 1/14 of an inch high.

Web browsers are designed to be very forgiving of errors in CSS. If a browser doesn't understand a unit or property, it usually just ignores it instead of breaking the entire page layout.

A 'twip' (twentieth of a point) is another typographic unit, primarily used in some software environments. There are 1440 twips to an inch.

Legibility refers to how easily individual characters can be distinguished. Readability refers to how easily blocks of text can be read. A font can be legible but have poor readability if the line spacing or character spacing is off.

While we often think of a pixel as an absolute dot on a screen, in CSS, the 'px' unit is a 'reference pixel'. It is defined as being the visual angle of one pixel on a 96 DPI display at an arm's length. This allows browsers to scale it for different screen densities.

The 'ch' unit in CSS is a relative unit that corresponds to the width of the '0' (zero) character in the current font. This is useful for creating layouts where element widths should be based on character counts.

Johannes Gutenberg's invention of the printing press with movable type in the 15th century revolutionized communication. The type was cast from a metal alloy and measured in points, a system that has conceptually survived for over 500 years.

Serifs are the small lines attached to the end of a stroke in a letter (like in Times New Roman). Sans-serif fonts (like Arial) lack these lines. Serifs are traditionally considered more readable for long blocks of print text, while sans-serif is often preferred for digital displays.

The Didot point is the typographic point used in the traditional French typographic system. It is slightly larger than the Anglo-American point (1 Didot point ≈ 1.07 PostScript points), leading to different pica and cicero sizes.