Caslon shares the irregularity characteristic of Dutch Baroque types. It is characterized by short ascenders and descenders, bracketed serifs, moderately-high contrast, robust texture, and moderate modulation of stroke. The A has a concave hollow at the apex, the G is without a spur. Caslon's italics have a rhythmic calligraphic stoke. Characters A, V, and W have an acute slant. The lowercase italic p, q, v, w, and z all have a suggestion of a swash.
Caslon's earliest design dates to 1722. Caslon is cited as the first original typeface of English origin, but some type historians point out the close similarity of Caslon's design to the Dutch Fell types.
The Caslon types were distributed throughout the British Empire, including British North America. Much of the decayed appearance of early American printing is thought to be due to oxidation caused by long exposure to seawater during transport from England to the Americas. Caslon's types were immediately successful and used in many historic documents, including the U.S. Declaration of Independence. After William Caslon I’s death, the use of his types diminished, but saw a revival between 1840–80 as a part of the British Arts and Crafts movement. The Caslon design is still widely used today. For many years a common rule of thumb of printers and typesetters was When in doubt, use Caslon.
Several revivals of Caslon do not include a bold weight. This is because it was unusual practice to use bold weights in typesetting during the 18th century, and Caslon never designed one. For emphasis, italics or a larger point size, and sometimes caps and small caps would be used instead.