Italics in Mac OS X: Sometimes the text in italics is too small (or too big)

Posted by Pierre Igot in: Macintosh
January 18th, 2006 • 2:47 pm

This is something that has been puzzling me for a long time. It has been a problem in Mac OS X for as long as I can remember, and appears to be associated to the underlying text rendering technology used by the system.

In a nutshell, the problem is the following: In certain circumstances, with certain fonts at certain font sizes, text in italics looks smaller (or bigger) than text in roman characters.

Here’s an example that everyone should be able to reproduce. In Safari, set your standard font size to 16 pt (in Safari’s preferences, under “Appearance”). Then load this page.

It’s a page that uses a Times font for the body text and, as far as I can tell, with the standard font size set to 16 pt in Safari’s preferences, the font size for the text of this page as rendered in Safari is Times New Roman 14 pt.

Now scroll down to the paragraph starting with “The straw man is being set up here…,” and check out the 10th line in that paragraph, which should be the line starting with “example), and what it means” Note the word in italics (“means”). Doesn’t it look smaller than the rest of the text to you? It certainly does on my machine:

Times New Roman italics 14 pt

If I blow this up, you can see quite clearly that the characters in italics are one pixel shorter than the other characters:

Text zoomed in

Normally, the top edge of the text should be aligned with the bars in the roman “t” and “f” characters that enclose the word in italics, as it is when the text is in roman characters:

Times New Roman roman 14 pt

So what’s going on here? I tried a few things in order to better circumscribe the problem… and I noted the following.

The problem doesn’t just affect Safari. The same text is also rendered improperly in Camino, for example. And if I copy the text and paste it into an empty TextEdit document and make sure it’s in Times New Roman 14 pt, I get the same problem in the same location in TextEdit.

The problem only affects text with a font size of 14 pt. If I make the text bigger or smaller, the problem disappears.

The problem only seems to affect a small number of fonts. I was able to reproduce it with Times New Roman and Times, but not with several other serif fonts I have on my machine. Interestingly, I was able to reproduce a similar problem with the Garamond font that I have on my machine and seems to have come with Microsoft Office, but the actual problem is the opposite. This time the text in italics is too big:

Garamond 14 pt

Since the problem occurs in a variety of applications, I have to suspect a problem with the underlying font rendering technology used by Mac OS X. But I find it surprising that this problem has been around for years and that no one at Apple appears to have noticed it, or done whatever is necessary to fix it. The Times New Roman and Garamond fonts I have might be Microsoft TrueType fonts, but the only Times font that I have on my system at this point is the “.dfont” font file that’s located in the “Fonts” folder inside the system’s own library folder. And I am able to reproduce the problem with that font as well, so it’s not just a problem with a couple of third-party fonts.

It’s hard to research this particular problem on the Web, because the key words used to describe it are so common (small, font, text, italics, etc.). So I haven’t found anything about this particular problem anywhere.

3 Responses to “Italics in Mac OS X: Sometimes the text in italics is too small (or too big)”

  1. MacDesigner says:

    I don’t think this can be laid at the feet of the rendering technology as much as the limitations of display technology. I copied and pasted the text into word and printed both a PDF and a laser print. In both the PDF and laser print the text is the correct size. If I enlarge the text on screen in Word and Safari it is the correct size.

    Also based on your pictures it is missing 1 pixel from the height. Due to the unusual size of 16 pt, it maybe a compromise inorder to help the font retain as much of it’s normal look as is possible with pixel based displays. Most fonts are designed with set sizes in mind. 6pt, 8pt, 9pt, 10pt, 11pt, 12pt, 14pt, 18pt, 24pt, etc. 16pt is not a standard size and not even a selection in the font menus. Therefore the computer must create a font size. It would be similar to enlarging 2 photos of different resolutions. As they enlarge one would retain more detail than the other as one has more pixel information to display.

    The best people to ask about this would be a font desinger. They spend years creating fonts and would probably be able to tell you all the problems of display versus print fonts. Or you could find some books such as “Thinking with Type : A Critical Guide for Designers, Writers, Editors, and Students,” which talk about the evolution of type and how display only types were developed.

    This in my opinion is more an example of the limitations of pixel based displays versus postscript printing technology.

  2. Pierre Igot says:

    My problem is that this problem only occurs with a few fonts (Times, Times New Roman, Garamond). So clearly there are ways to avoid the problem, which all other fonts manage to do successfully.

    Whether it’s a problem with the fonts themselves or the rendering technology, it seems to me that the system should be able to render these italic fonts in a way that looks right, and that the problem with these particular fonts is either a bug or a flaw in the algorithm used to render the font.

    I also don’t think that any font size between 9 and 24 can be considered “abnormal” or “unusual.” With screen resolutions increasing, and with most programs supporting some kind of zoom setting, we need to have an underlying font rendering technology that can do a proper job at any size.

    The days of bitmap screen fonts with fixed 9 pt, 10 pt, 12 pt, 14 pt and 18 pt designs are far in the past. It could be that some fonts still come with set sizes either in fact or in mind. But I suspect that there are many fonts that don’t, and that Mac OS X renders just fine at all screen sizes.

    This problem with these particular fonts at 16 pt still looks like an aberration to me.

  3. MacDesigner says:

    So the fonts that suffer from this problem are the oldest fonts on computer systems. The fonts first designed when computer layout was in its infancy. Truth be told some font sizes between 9 and 24 pt can be considered abnormal. They are not the usual sizes used. Many fonts since have been designed with displays in mind, these were not. And I doubt they have been updated.

    Quark used to be horrible at displaying fonts at odd sizes. Designers had to print the file to see how well the tracking and leading looked. InDesign upped the bar and Quark has improved, but when you use fonts originally designed with print in mind for display, you will get some oddities because pixels do not always relate to points on a 1:1 basis.

    And again it’s not the rendering technology at fault its the info supplied by the font file. Which is the exact reason many fonts were designed as display fonts, designers hate when the design created is undermined by technological limitations. That’s why CSS was developed. But Times is still used because it’s a default font that 99% of computer users have installed on their systems.

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