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

Picture boxes—rectangles
13.1. The picture environment 291
The box commands \framebox, \makebox, and \savebox (Section 4.7.1)
are available in the picture environment but with an extended syntax. In
addition, there is another box command \dashbox:
\makebox(x dimen,y dimen)[pos]{text}
\framebox(x dimen,y dimen)[pos]{text}
\dashbox{dash len}(x dimen,y dimen)[pos]{text}
The dimensional pair (x dimen, y dimen) defines the width and height
of the rectangular box in units of \unitlength. The positioning argument
pos determines how the text is located within the box. It may take on
values:
[t] top The input text appears—centered horizontally—below the upper
edge of the box.
[b] bottom The input text appears—centered horizontally—above the
lower edge of the box.
[l] left The input text begins—centered vertically—at the left edge of
the box.
[r] right The input text ends—centered vertically—at the right edge of
the box.
[s] stretch The input text is stretched horizontally to fill up the box,
and centered vertically.
Without the optional argument pos, the input text is centered vertically
and horizontally within the box.
These positional values may be combined two at a time:
[tl] top left The text appears at the upper left.
[tr] top right The text appears at the upper right.
[bl] bottom left The text appears at the lower left.
[br] bottom right The text appears at the lower right.
The order of the values is unimportant: tl has the same effect as lt.
These box commands are to be used as pic elem in the placement
commands \put and \multiput. The box is so placed that its lower left
corner is at the position given by the coordinate pair in the placement
command.
\put(1.5,1.2){\framebox(2.5,1.2){center}}