There are three categories of serif typefaces: oldstyle, modern, and slab serif. We will discuss oldstyle and modern on this page and slab serif on the next.
Below, on the left, the word Freestone appears in Baskerville, an oldstyle typeface, and, on the right, in Onyx, a modern style typeface. Both are set at 18 points.
The first difference between the two styles is the angle of the serif. Oldstyle serifs angle downward, while modern ones form a straight line. Compare the letters n in the two examples above.
The second difference between them is the level of contrast between the thick and thin parts of the letterforms. In the oldstyle example, the thick/thin transition of the letters e and o is slight, making the letterforms appear thicker overall. In the modern style, the tops of the letters e and o are very thin compared to the sides, making the letterforms seem thinner than the oldstyle.
Finally, oldstyle letterforms have a diagonal stress, while modern style ones have a vertical stress. In other words, if you drew a line through the thinnest parts of this oldstyle , it would run at a diagonal, but if you did the same with this modern style , it would run in a straight line from top to bottom.
Additionally, oldstyle letterforms have wider bowls, which refers to the amount of space between the sides of open letterforms such as e and o. Some designers believe that this gives text an open, friendly appearance. While others think that the horizontal serif and well-defined thick/thin stroke of modern style typefaces looks more formal. Both are good choices depending on the image you want your publication to convey.
When it comes to body text, some professionals prefer oldstyle typefaces because, at least in smaller point sizes, the thin strokes of modern typefaces can almost disappear, making it harder for readers to identify letterforms. Yet, others argue that the thin strokes give the page a lighter appearance. There is clearly no consensus on the matter, but knowing the facts, you decide for yourself.