Specs: a Guide for Type Classification and Font Metrics

Font metrics uses information about words and aspects of individual characters to make the reading experience easier and more pleasing to the eye of the viewer. The ratio of ascenders, descenders, and the weight of the character’s stroke to the x-height are determining factors in a font’s legibility and aesthetics.

In addition to precise metrics, this guide contains font specimens, historical context, distinguishing characteristics, and examples of various sizes to better visualize each face in context. It aims to illustrate these principles in a way that is easy to reference and put into practice.

“The fact is that there are not many people who can space letters well, and those that can do it generally learnt it from making letters rather than using them.”
— Matthew Carter

50 unique fonts are organized by their classification, which are then ordered by the time period in which that style originated, then further alphabetized.

The "Haxph" diagram contains a capital 'H' for gauging cap-height, an 'x' for the base reference in all calculations, a 'p' and 'h' to measure ascender and descender ratios, and my favorite, the lowercase 'a' which can be single or double story, often lending character and differentiation to otherwise similar fonts.

There is a type catalog created by the Texas State Communication Design program which contains fonts that are tried and true and beautifully designed. This reference builds upon those core classics like Baskerville, Minion, Didot, and Gill Sans, and adds even more fonts, some similar but unique in their nuances.

The regular cut of each face is compared to Adobe Jenson Pro, developed by Robert Slimbach, as a frame of reference for good proportion and legibility.

On the left:

Point-by-point gauge measuring vertical proportions as related to Adobe Jenson and stroke weight (17–20% is optimal for legibility)

A lowercase 'x' set at the point size which visually equates it to Adobe Jenson's 'x' at 100 pt.

A paragraph of text set 10/13 and justified

The line length in points, picas, and inches of 2 lowercase alphabets

On the right:

The designer, foundry, year released, and brief history

Upper and lowercase characters set at 100 pt.

A specimen set at 36 pt.

An upper and lowercase character pair set at various text and display sizes.