Font sizes

The "" command lets you change the magnification of your document. You can effectively fine tune the magnification by using the "11pt" and "12pt" style options. For example, instead of increasing the magnification from 4 to 5, you can switch to the "12pt" style option. There are differences—e.g., magnification affects the space you get from " "—but the fonts will at least be roughly the same size either way. The "11pt" option gives a half-step, somewhat like "4.5", if the latter were permitted. Sometimes you want to use smaller font sizes for a single slide, in order to fit in that little bit of extra material, or to use larger font sizes, so that the few things you have to say on a slide don't look too lonely. You can't changing the magnification in the middle of the document, but you can change the size of the fonts with the command
\begin{MD}
\ptsize{n}
\end{MD}
This switches to the font sizes that are in effect when you use the "<n>pt" option. Actually, <n> can be 8, 9, 10, 11, 12, 14 or 17, whether you have "art<n>.sty" or not.