One of the most commonly asked questions is how to change font sizes in LaTeX beyond those offered by \tiny through \Huge. There are a number of different font parameters that can be selected using the New Font Selection Scheme. In particular, one can select the exact font size and line height (the leading). To select a 10pt font on 12pt leading, one can use

\fontsize{10}{12}%
\selectfont

Of course, 10 and 12 can be replaced with any values. Since \fontsize uses \@defaultunits (see here), units other than pt can be used.

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