Guide to LaTeX (4th Edition) (Tools and Techniques

334 Chapter 15. Presentation Material
Margins
Normally the material within a slide is centered vertically. The declaration
commands
\centerslidefalse and \centerslidetrue
turns this centering off and on, respectively. Without centering, the text
is pushed to the top of the slide.
The text is left justified by default, with a ragged right margin. This
can be changed with
\raggedslides[len]
where len is the maximum space between the end of the line and the right
margin. Omitting len produces a ragged right margin, while a value of 0 pt
yields right justification; giving 2 em, say, creates a semi-ragged margin.
The margins between the slide area and the edge of the page are set
with the commands
\slideleftmargin \sliderightmargin
\slidetopmargin \slidebottommargin
which are all set initially to 0.6 in. Since these are commands, not lengths,
they must be changed with \renewcommand.
Framing
The slide area can be framed, the default being a rectangular box like that
produced by \fbox (which is exactly what it is). The frame style can be
chosen with
\slideframe[cmds]{style}
The possible values for style are plain (the default) or none. The optional
cmds are settings to adjust the frame parameters, such as \fboxrule
and \fboxsep. By including the fancybox package, one also has shadow,
double, oval, and Oval as allowed values for style, with their corresponding
parameters (Section 4.7.9).
All frames make use of the lengths
\slideframewidth and \slideframesep
for the frame thickness and separation from text. These may only be
altered (with \setlength) outside the \slideframe command; in the
optional cmds, one must alter \fboxrule and \fboxsep directly.
It is possible to define one’s own frame style with
\newslideframe{new style}[cmds]{\box cmd{#1}}