Text anti-aliasing: Windows’ ClearType vs. Mac OS X’s Quartz Text Smoothing

Posted by Pierre Igot in: Macintosh
April 28th, 2004 • 4:33 am

This is one of these issues that I have been wondering about for a long time… See, I have Virtual PC installed on my G4, and it’s running Windows XP Home Edition. I don’t use it very often, and certainly haven’t spent any time trying to customize Windows XP’s configuration.

Now a new debate between Going Nowhere and Scobleizer raises some new issues for me.

It all starts with Robert Scoble (a long-time blogger and more recently a Microsoft employee) claiming that Microsoft’s ClearType technology is far superior to Mac OS X’s anti-aliasing.

Going Nowhere retorts that he doesn’t agree at all, and provides screen shots to prove his point.

Scobleizer checks the screen shots and reiterates that there is “no contest“.

Finally, Going Nowhere takes Scobleizer to task regarding his assumptions and attitude.

Like Going Nowhere, I am not a specialist. But looking at his screen shots, several things appear obvious:

  1. The anti-aliasing in Mac OS X looks far closer to what the font actually looks like in print. Unless I am mistaken, that’s exactly what the purpose of anti-aliasing is, isn’t it? To make text on screen look more like text in print. The anti-aliased Times font in Windows looks nothing like actual Times characters in print.
  2. It could be argued that anti-aliasing is not necessarily about making on-screen text look like printed text (although Scobleizer doesn’t make that point), but only about making on-screen text more pleasant to read. Here again, however, I fail to see how the Windows XP text is easier/more pleasant to read than the Mac OS X text. On the contrary, the font weight looks like it’s changing wildly from one character to the next, especially in the boldface text. And the shapes are still much more angular than they would be in print, which makes them less pleasing to the eye.
  3. The Japanese text is not anti-aliased at all in the Windows XP screen shot, so the comparison is irrelevant there.

The bottom-line, to me, is that there is a reason why anti-aliased text is trying to look like printed text: It’s because print-like quality is the ultimate goal! The vast majority of the typefaces used today were designed for print. To me, a on-screen font that looks more like its printed version is obviously going to be more pleasant to read, because it’ll be closer to the font designer’s actual design.

The other interesting point is that Scobleizer is only able to say that ClearType text looks better to him on certain types of displays and after much tweaking of the settings — which is a typical Microsoft attitude: requiring users to tweak their settings vs. things working right out of the box. Mac OS X does give you four different settings for text smoothing and is not particularly smart at guessing which one is the best for your display. And sometimes (after a massive crash) it still forgets your setting and reverts to the default “Best for CRT”. But at least the setting is easy to find (under “Appearance” in System Preferences) and change.

Finally, all this sort of explains why I thought font anti-aliasing in Windows XP Home Edition in my Virtual PC environment wasn’t working very well: I probably haven’t even turned it on!

10 Responses to “Text anti-aliasing: Windows’ ClearType vs. Mac OS X’s Quartz Text Smoothing”

  1. Patrick Wynne says:

    Just a note: The first link in the argument (“ClearType technology is far superior”) actually points to one of Zeldman’s posts about his OS X troubles, not a Scoble blog entry.

  2. Patrick Wynne says:

    Heh heh, or y’know, I could actually *read* the Zeldman post to see that he does talk about anti-aliasing. Oops.

  3. Pierre Igot says:

    Thanks for the correction. Scoble’s blog design leaves a bit to be desired, shall we say.

  4. Robert Scoble says:

    Actually, if you talk with the engineers at either Apple or Microsoft, anti-aliasing, or technologies like ClearType (which really isn’t anti-aliasing, but rather a technology that uses the RGB display technology to increase resolution) are both ways to make fonts easier to read, not to make them more faithful to print.

  5. Pierre Igot says:

    Robert: Thanks for your comment. As I said, I’m not a specialist, and certainly do not have the inside scoop about MS or Apple technology. However, it strikes me as strange that matching print should not be the goal, since most fonts are designed specifically for print. (I know that MS in particular has developed some fonts especially for on-screen reading, but these are exceptions.) In any case, I think you will agree from the screen shot provided by Going Nowhere that Mac OS X anti-aliasing looks much closer to what the Times font looks like in print than the Windows XP anti-aliasing does. Whether that translates into the text being easier to read on-screen is obviously another matter, and a highly subjective one at that.

  6. Robert Scoble says:

    Well, print is useful to study but now that we’re creating type for on screen, we need to look at that as a separate thing than print. Learn from the old, but design for the new. Designing fonts for readability on screen (most screens are 72 DPI to 96 DPI, while print is usually 600 DPI or higher) is different than for print. Go and listen to the Bill Hill videos over on Channel9 http://channel9.msdn.com (click on videos and look for Bill Hill, he’s the head of typography here).

  7. Derek says:

    Robert, I agree with that old maxim about “learn from the old, design for the new” but I think that Pierre’s point here is not about designing new fonts. Clearly some beautiful work has been done on computer typefaces.

    The point is about whether we can easily read text displayed on computer screens. Right? But we all learn to read on print, and that human dependence on print is not likely to change anytime soon, so then it makes sense to ask to what degree what we see on the screen is like what we see in print.

  8. John Kheit says:

    I did an article on this a while back that may be of interest to the debate. To me it’s it boils down to this. At small font sizes you need to tune down the amount of “halo” effect use in the antialiasing. ClearType does that. At medium to larger sizes, having more “halo” effect smooths things nicely. I proposed a “MultipleMasters” type of approach to antialiasing as a more optimal solution. Namely the display layer should crank down the “halo” effect as you get down to smaller font sizes (say 14pt and smaller) and crank it up at higher points.

    Anyway, here’s the link:


  9. Adam Sampson says:

    Having played around with antialiased rendering for a while, I’ve found that display gamma makes a considerable different to how good it looks. If I recall correctly, Mac and Windows systems have different default gamma settings — so isn’t it quite likely that the Mac rendering model will look good on a Mac, and the Windows model good on a Windows machine?

    The other thing I’ve discovered is that almost everybody has different preferences for how their text is rendered, so it’s always going to be difficult to argue that one method is superior to all others.

  10. Pierre Igot says:

    I agree that gamma settings probably have some impact. However, the screen shot provided by Going Nowhere can be viewed on both PCs and Macs, with their respective gamma settings. I’ve tried fooling around with the gamma setting on my monitor while viewing GN’s screen shot, and I don’t really see major variations.

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