Very interesting... thank you, Rasmus!
Indeed Consolas, the font I was using, doesn't have the check mark unicode character (U+2713). Switching to DejaVu Sans Mono solved the problem.

Giacomo


On Wed, Mar 5, 2014 at 1:01 PM, Rasmus <rasmus@gmx.us> wrote:
Giacomo M <jackjackk@gmail.com> writes:

> Dear all,
> nothing of crucial importance for the sake of humanity, but when I realign
> (C-c C-c) the following table:
>
> | entry1 | \check |
> | entry2 | X |
>
> with pretty-entities toggled (C-c C-x \), columns are not perfectly aligned.

Probably you are using different fonts for check and the rest.

Use M-x describe-char and look at the line starting with

   The component character(s) are displayed by these fonts

Hope it helps,
Rasmus

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Hooray!