Most people outside the design world know that Light is lighter than Regular and Bold is heavier than Regular. Most people who know English will recognise Semibold (or Demi-bold) as being half-heavy and Thin as being thinner than Light.
Most designers are used to the Medium weight typically being somewhere between Regular and Semibold.
Some issues with in-between styles (which are not available in just any font) are solved through the prefixes Extra and Ultra, meant to intensify the meaning of an adjective. For example, Extralight would be lighter than Light, while Ultrabold would be heavier than Bold. However, these prefixes cannot be used with Regular. Since Regular is the default font style, Extraregular (extremely regular) or Semiregular (half-regular) would be oxymorons. That is why type designers use other terms to refer to intermediate weights between Light and Regular, which sometimes complicates things for graphic and layout designers.
Roman
The term Roman has multiple meanings. Initially, in the 15th and 16th centuries, when printing technology invented by Johannes Gutenberg spread throughout the world, this word was used to refer to upright styles. For instance, the term is used in this sense in the name of the Times New Roman typeface (which is why calling its italic variant Times New Roman Italic is not quite correct — calling it just Times New Italic would be more appropriate).
The term Roman can also refer to one of the font weight options, being a synonym to the word Regular, or imply that the typeface is somehow a take on the Roman capitals. This word might also be used for language support when a font covers only the Romance languages, such as French, Portuguese, and Romanian.
Jenson Roman. Venice, 1470. Image: Riccardo Olocco, Medium
Alphabet from the Trajan Column. Eric Gill, 1909. Image: Victoria and Albert Museum
Type designer Thomas Phinney and curator at Letterform Archive Stephen Coles advise against using this word to refer to a font weight.
Book
A century ago, default typeface weights were heavier than today’s Regular, and the Book style — applied when typesetting books — was lighter than the default weight but darker than the Light style. At the same time, the potential scope of metal type’s application affected not just its weight and contrast, but also its sizes, and if, for instance, Futura’s bold and light styles were cast in the range of 8 to 84 points, Futura Book (Futura Buchschrift) was cast in the range of 6 to 12 points.
Futura Buchschrift, 1933. Image: Spieki Leaks
This is not enough to come to a clear conclusion on how the Book style should look. On the one hand, it has to be lighter than Regular — so that the letters are not too bold when printed on bulked or offset paper; on the other hand, it should be heavier so that it is easier to read in smaller sizes.
Today, the FontLab font editor suggests considering Book styles weight-wise to be the same as Regular or Normal. That’s exactly how ITC Font Foundry applies this term for their fonts, with this word replacing the word Regular in their projects. Finally, some designers believe that the word Book is to be used to refer to the optical size rather than the weight.
ITC Avant Garde Gothic Book
ITC Franklin Gothic Book
ITC Garamond Book
Blond
We don’t know exactly when this term came about, but it is now actively used to refer to the style between Light and Regular by, for instance, Fred Smeijers and other authors from the Type By label. Alphabettes community member Robin Mientjes also suggests using this term. Head of the KABK Type and Media department Erik van Blokland and type designer Kent Lew also agree that a style slightly lighter than Regular is exactly what Blond means.
