It’s
important to distinguish between page size (as defined
in the Document Setup dialog box for your document) and paper
size (the sheet of paper, piece of film, or area of the printing
plate you’ll print on). Your page size might be US Letter (8.5-by-11
inches), but you might need to print on a larger piece of paper or
film to accommodate any printer’s marks or the bleed and slug areas.
The
list of paper sizes available to InDesign comes from the PPD (PostScript printers)
or from the printer driver (non-PostScript printers). If the printer
and PPD you’ve chosen for PostScript printing support custom paper
sizes, you’ll see a Custom option in the Paper Size menu.
Most
imagesetters can accommodate regular paper sizes, such as letter
and tabloid, as well as transverse orientation, where the regular
page size is rotated 90° when printed. The transverse orientation
is often a more efficient use of imagesetter media.

Page size and orientations for imagesetters
- A.
- Letter (tall orientation)
- B.
- Custom
page size (tall orientation)
- C.
- Letter
(transverse orientation)
Paper
sizes are listed by familiar names (such as Letter). The dimensions
define the limits of the imageable area—the total paper size, less
any unprintable border used by the printer or imagesetter. Most
laser printers cannot print to the exact edge of a page.
If
you select a different paper size (for example, if you change from
Letter to Legal), the document is rescaled in the preview window.
The preview window displays the entire imageable area of the selected
page; when the preview size is changed, the preview window automatically
rescales to include the imageable area.
Note: The
imageable area will vary by PPD file, even for the same paper size
(for example, Letter), because different printers and imagesetters
define the sizes of their imageable areas differently.

Comparison of printing a letter-size page on Letter, Letter.extra,
or Tabloid paper
Note: The preview
in the lower-left area of the Print dialog box indicates whether
you have enough space to include all printer’s marks and the bleed
and slug areas.