If only a single value is given, this is used for both the width and height.
page is set and is smaller than the size of the layout, a rectangular
array of pages of the specified page size is overlaid on the layout, with
origins aligned in the lower-left corner, thereby partitioning the layout
into pages. The pages are then produced one at a time, in
page only works for PostScript output. For other types of output,
use another tool to split the output into multiple output files,
viewport to generate multiple files.