CM clearer than CMsuper? After applying \usepackage[T1]{fontenc}, fonts get blurry

minimum working code:

\documentclass{article}
% \usepackage[T1]{fontenc}

\begin{document}

abc
ABC
123

\end{document}


It opens as pdf in Mac's preview and Acrobat X respectively.

The left is original, the right uses T1.

Should I assume the T1 encoding or CMsuper is not anti aliased or so?

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I have seem similar issues, but I think it is best to see how it looks in Acrobat. – Peter Grill May 19 '11 at 0:05
They are using different fonts, one is cmr10(CM), the other is sfrm1000(CM-super). – Ma Ming May 19 '11 at 0:18

2 Answers

This is a bit tricky to explain.

There are two possible issues here.

The more obvious one is if you are not using an outline version (type 1) of the T1 fonts (eg, CM-Super), and are instead getting the bitmap (type 3) "EC" version. You can tell if this is the case because after zooming in very far you will see that the glyphs are "jagged". Alternatively, you can check the name of the embedded font (eg, sfrm1000 for CM-Super). Since the full set of type 1 CM-Super fonts is many megabytes, many tex distributions do not install it by default. See this FAQ answer and this one. You may have to install CM-super (or alternatively use lmodern).

The second possible issue is that the CM-Super fonts are indeed not as well constructed as the bluesky computer modern. This is a more subtle effect, and may not show up depending on your OS and your PDF viewer. It almost certainly is invisible when you print the PDF. Lmodern is a little better in this regard, but still not as good as computer modern.

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Yes, I saw many type 3 fonts used in my pdf. Now I am installing the CM-Super fonts. Should work this time. – colinfang May 19 '11 at 4:28
Done. Now all my type 3 fonts turned to type 1 and the words in pdf looks crisp. – colinfang May 19 '11 at 4:32
bluesky cm was once a commercial product: since it was a selling point of the commercial distributions that came with it, a lot of work was put into optimising its performance. by contrast, cm-super is a much larger set of fonts, done by a single person using standard tools: when it was released, the announcement disclaimed issues of quality. as it happens, i think cm-super is very good (it covers lots of encodings, too, not just t1), but for t1-only requirements, the latin modern fonts are better still. – wasteofspace May 19 '11 at 10:52

I've found that the Computer Modern fonts look blurry when using T1 encoding. Using the Latin Modern fonts instead solves the problem:

\usepackage[T1]{fontenc}
\usepackage{lmodern}

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Yes, indeed. :) – colinfang May 19 '11 at 0:27