scalefnt – Rescale fonts to arbitrary sizes

\scale­font{2} se­lects the cur­rent font in twice the cur­rent size. \scale­font{.75} re­duces the cur­rent font size by three quar­ters.
Note that the ef­fec­tive­ness of such op­er­a­tions de­pends on the LaTeX font se­lec­tion for that font; it will typ­i­cally work well for or­di­nary Type 1 fonts, but METAFONT fonts are usu­ally set up to work only at a dis­crete set of sizes.