scalable-fonts-allowed

scalable-fonts-allowed is a variable defined in `C source code'.
Its value is

nil

Documentation:
Allowed scalable fonts.
A value of nil means don't allow any scalable fonts.
A value of t means allow any scalable font.
Otherwise, value must be a list of regular expressions. A font may be
scaled if its name matches a regular expression in the list.
Note that if value is nil, a scalable font might still be used, if no
other font of the appropriate family and registry is available.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.