Making Postscript and PDF International
How to lay out a PostScript or PDF document so it prints well on both Letter and A4 paper.
Palme, J., "Making Postscript and PDF International", RFC 2346, DOI 10.17487/RFC2346, May 1998, <https://www.rfc-editor.org/info/rfc2346>.
@misc{rfc2346,
series = {Request for Comments},
number = 2346,
howpublished = {RFC 2346},
publisher = {RFC Editor},
doi = {10.17487/RFC2346},
url = {https://www.rfc-editor.org/info/rfc2346},
author = {J. Palme},
title = {{Making Postscript and PDF International}},
pagetotal = 6,
year = 1998,
month = may,
} RFC text
Contents
Network Working Group J. Palme
Request for Comments: 2346 Stockholm University/KTH
Category: Informational May 1998
Making Postscript and PDF International
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
Certain text formats, for example Postscript (MIME-Type:
application/postscript; file extension .ps) and Portable Document
Format (MIME-Type: application/pdf; file extension .pdf) specify
exactly the page layout of the printed document. The commonly used
paper format is different in North America and the rest of the world.
North America uses the 'Letter' format, while the rest of the world
mostly uses the ISO-standard 'A4' format. This means that documents
formatted on one continent may not be easily printable on another
continent. This memo gives advice on how to produce documents which
are equally well printable with the Letter and the A4 formats. By
using the advice in this document, you can put up a document on the
Internet, which recipients can print without problem both in and
outside North America.
A very short summary of the advice in this document: If you are using
U.S. Letter paper format, ensure that both the left and right margins
are at least 21 mm (0.8 in). If you are using A4 paper format, ensure
that both the top and bottom margins are at least 33 mm (1.3 in).
Table of Contents
1. Introduction 2
2. Two methods for printing on different paper formats 2
2.1 Method 1: Use wider margins 2
2.2 Method 2: Print with reduced size 3
2.3 Method 3: Buy paper in the A4 size 4
3. Acknowledgements 4
4. Security Considerations 4
5. References 4
6. Author's Address 5
7. Full Copyright Statement 6
1. Introduction
Certain text formats, for example Postscript (MIME-Type:
application/postscript; file extension .ps) and Portable Document
Format (MIME-Type: application/pdf; file extension .pdf) specify
exactly the page layout of the printed document. The commonly used
paper format is different in North America and the rest of the world.
North America uses the 'Letter' format, while the rest of the world
uses the 'A4' format.
The North American Letter format is 216 x 279 mm (8.5 x 11 in) while
the ISO standardised A4 format is 210 x 297 mm (8.3 x 11.7 in). The
Letter format is thus 6 mm (0.2 inches) wider, while the A4 format is
18 mm (0.7 inches) taller.
This means that documents formatted on one continent may not be
printable on another continent. It is oboviously desirable that
documents on the Internet are printable on all continents. This paper
gives advice on how to achieve this.
This memo is not intended for HTML documents, but the advice may be
of value also for HTML developers in case they are using fixed-size
graphics and fixed WIDTH sizes of objects in HTML documents.
2. Three methods for printing on different paper formats
2.1 Method 1: Use wider margins
Paper format
you use when
converting
the document Suggested minimal margins
to Postscript Paper
or PDF orien- Suggested change Left Right Top Bottom
tation of margins
------------ ----------- ----------------- ----- ----- ----- -----
A4 Portrait Add 18 mm (0.7 20 mm 20 mm 33 mm 33 mm
(upright, inches) to the top 0.8" 0.8" 1.3" 1.3"
vertical) of page and bottom
of page margins
A4 Landscape Add 18 mm (0.7 33 mm 33 mm 15 mm 15 mm
(lying, inches) to the 1.3" 1.3" 0.6" 0.6"
horizontal) left and right
margins
Letter Portrait Add 6 mm (0.2 20 mm 26 mm 15 mm 15 mm
(upright, inches) to the 0.8" 1.0" 0.6" 0.6"
vertical) right margins
Letter Landscape Add 6 mm (0.2 15 mm 15 mm 21 mm 21 mm
(lying, inches) to the top 0.6" 0.6" 0.8" 0.8"
horizontal) of page and bottom
of page margins
The reason why you have to add 18 respectively 6 mm to both the top
and the bottom margin is that you do not know what kind of printer
the recipient uses, and different printers feed paper in different
ways, requiring the margin to be added either at the top or the
bottom of the paper. Left and right margins on any paper format
should be at least 20 mm wide to accomodate filing with ISO 838 hole
punches.
Note: Ensure that also headers, footers, and page numbers are within
the suggested minimal margins. Many word processors put headers,
footers and page numbers outside the specified text margins.
2.2 Method 2: Print with reduced size
This is a method useful for the recipient of a document with the
wrong paper size: The recipient sets the printer to print with
reduced size. When the sender produces the PDF or Postscript files,
the sender should 'print' with 100 % size, but when the recipient
prints the PDF or Postscript files, and if the program for printing
PDF or Postscript files allows this, the recipient should print the
document with 94% or less of full size. Many programs for printing
Postscript files do not allow this. In that case, the recipient can
convert a Postscript document to PDF format and then print it with
the PDF printing program. This requires, however, that the recipient
has the Adobe Acrobat Distiller program, which is not freeware.
Recent versions of the freeware ghostscript can also convert to PDF
format. The user may also have to specify the paper size as the
actual paper size loaded in the printer, not the paper size specified
when the document was converted to PDF or Postscript format.
It is also possible to edit the Postscript file, and add a scale
command to it, before sending it to the printer.
Method 2 can be more difficult for the recipient, who has to manage
these settings himself. However, manufacturers of printing software
may in the future make method 2 easier by making this service
automatic, perhaps controlled by a 'shrink to fit paper size'
checkbox in the printing window and a 'default shrink to fit paper
size' preference setting.
In general, the authors of this RFC recommend PDF as the prefered
formatted document distribution format over Postscript, not only
because PDF printing programs typically feature a 'shrink to fit'
option to handle different paper sizes elegantly, but also because
PDF has built-in per page data compression, PDF files can be
displayed without being fully downloaded, PDF is more portable, PDF
has a better method of rendering fonts not available in the printer
and PDF allows to embed URLs.
2.3 Method 3: Buy paper in the A4 size
People in North America who often need to print international
documents might choose to buy paper in the A4 size. It is available
in the U.S. from many large paper distribution companies, and almost
all laser printers support it.
3. Acknowledgements
Markus Kuhn has provided many helpful suggestions on this document.
Adobe, Acrobat, Distiller, Exchange and Postscript are trademarks of
Adobe Systems Incorporated or its subsidiaries.
4. Security Considerations
Adherence to the recommendations in this memo will increase the
likelihood that a document will be readable, and look the same, to
all recipients, and thus reduce the risk of misunderstanding. The
recommendation does not in itself introduce any known new security
risks. Of course, there might be a risk that reliance on the
recommendations in this memo will make certain writers too sure that
their documents will look the same.
Postscript (TM) has well known security risks. These are discussed in
[MIME].
5. References
A4 Writing paper and certain classes of printed matter
- Trimmed sizes - A and B series, International
Standard ISO 216, International Organization for
Standardization, Geneva, 1975.
ANSI Bond Papers and Index Bristols - Common Sheet Sizes,
North American National Standard ANSI X3.151, North
American National Standards Institute, 1987.
ISO Paper - Holes for general filing purposes -
838 Specifications, International Standard ISO 838,
International Organization for Standardization,
Geneva, 1974.
Kuhn Markus Kuhn: International Standard Paper Sizes.
<URL:http://www.ft.uni-erlangen.de/~mskuhn/iso-
paper.html>.
PDF Tim Bienz, Richard Cohn, James R. Mechan: Portable
Document Format Reference Manual, Version 1.2, Adobe
Systems Incorporated,
<URL:http://www.adobe.com/supportservice/devrelation
s/PDFS/TN/PDFSPEC.PDF>.
MIME Freed, N., and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046,
November 1996.
6. Author's Address
Jacob Palme
Stockholm University and KTH
Electrum 230
S-164 40 Kista, Sweden
Phone: +46-8-16 16 67
Fax: +46-8-783 08 29
EMail: jpalme@dsv.su.se
7. Full Copyright Statement
Copyright (C) The Internet Society (1998). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
ISO Plain Language
On this page
§1Why a Document Made on One Continent May Not Print on Another
Some text formats describe the exact page layout of the printed result. The memo names PostScript (MIME type application/postscript, file extension .ps) and the Portable Document Format (MIME type application/pdf, file extension .pdf) as two of them. Because the layout is fixed in the file, a document laid out for one sheet size cannot simply be re-fitted to another without something being cut off or left short.
The two common sheet sizes differ. The North American Letter format is 216 x 279 mm (8.5 x 11 in). The ISO-standardised A4 format is 210 x 297 mm (8.3 x 11.7 in). Letter is therefore 6 mm (0.2 inches) wider, and A4 is 18 mm (0.7 inches) taller. The two differences are small, but a document placed for Letter leaves too little room at the top and bottom on A4, and a document placed for A4 has room to spare at the top and bottom but is too wide for Letter.
The memo's short version of its own advice is this. If you use US Letter paper, make sure both the left and right margins are at least 21 mm (0.8 in). If you use A4 paper, make sure both the top and bottom margins are at least 33 mm (1.3 in). The memo says it is not aimed at HTML documents, though the advice may help HTML authors who use fixed-size graphics or fixed width objects.
A PDF or PostScript file says exactly where everything sits on the page, so it is tied to one sheet size. Letter and A4 differ by a few millimetres in width and height, and that is enough to push part of a page off the sheet. The memo explains the differences and then gives three ways to avoid the problem.
| Paper format | Size in millimetres | Size in inches |
|---|---|---|
| Letter (North America) | 216 x 279 mm | 8.5 x 11 in |
| A4 (ISO standard) | 210 x 297 mm | 8.3 x 11.7 in |
§2.1Method 1: Use Wider Margins
The first method is to leave enough blank space around the content that both sheet sizes work. The table in the memo gives the margins to use for each combination of paper format and orientation, and the change to make when converting the document to PostScript or PDF.
For A4 in portrait, add 18 mm (0.7 inches) to the top and bottom margins, giving 20 mm (0.8 in) left and right and 33 mm (1.3 in) top and bottom. For A4 in landscape, add 18 mm (0.7 inches) to the left and right margins instead, giving 33 mm (1.3 in) on the sides and 15 mm (0.6 in) top and bottom. For Letter in portrait, add 6 mm (0.2 inches) to the right margin, giving 20 mm (0.8 in) left, 26 mm (1.0 in) right and 15 mm (0.6 in) top and bottom. For Letter in landscape, add 6 mm (0.2 inches) to the top and bottom margins, giving 15 mm (0.6 in) on the sides and 21 mm (0.8 in) top and bottom.
The memo explains why the extra room is added to the top and bottom rather than the sides: the sender does not know what printer the recipient has, and different printers feed paper in different ways, so the margin has to be there at either the top or the bottom. Left and right margins on any format should be at least 20 mm to allow for filing with ISO 838 hole punches. One practical warning: headers, footers and page numbers must also sit inside these margins, because word processors often place them outside the text margins.
Leave enough white space around the text that the smaller sheet still fits. The memo lists the exact margins for each paper size and orientation. The spare room goes on the top and bottom because the sender cannot know how the recipient's printer feeds the paper. Headers and page numbers have to move inside the margins too, because many word processors put them outside.
| Paper and orientation | Left | Right | Top | Bottom |
|---|---|---|---|---|
| A4 portrait | 20 mm | 20 mm | 33 mm | 33 mm |
| A4 landscape | 33 mm | 33 mm | 15 mm | 15 mm |
| Letter portrait | 20 mm | 26 mm | 15 mm | 15 mm |
| Letter landscape | 15 mm | 15 mm | 21 mm | 21 mm |
§2.2Method 2: Print With Reduced Size
The second method helps the recipient of a document that already has the wrong paper size. The sender produces the PDF or PostScript file at 100 percent size, and the recipient prints it at 94 percent or less of full size, if the printing program allows it. The memo notes that many programs for printing PostScript files do not allow this. In that case the recipient can convert the PostScript document to PDF and print it with a PDF printing program, which requires the Adobe Acrobat Distiller program, which is not freeware, or a recent version of the freeware Ghostscript. The recipient may also have to specify the paper size as the size actually loaded in the printer rather than the size recorded when the file was created. It is also possible to edit the PostScript file and add a scale command before sending it to the printer.
The memo is candid that this method is harder on the recipient, who has to manage these settings. It suggests that printing software makers could make it easier, for instance with a shrink to fit paper size checkbox in the printing window and a matching default preference.
On that theme the memo recommends PDF as the preferred format for distributing documents, for several reasons. PDF printing programs typically offer a shrink to fit option, PDF has built-in per-page data compression, PDF files can be displayed without being fully downloaded, PDF is more portable, PDF renders fonts that the printer does not have in a better way, and PDF allows URLs to be embedded.
The recipient can print the document slightly smaller than full size, at 94 percent or less, so it fits the sheet they have. That is a setting the recipient has to make, which is why the memo prefers the other methods. The memo also recommends sending PDF rather than PostScript, because PDF files are smaller, can be shown before they finish downloading, and print correctly on more machines.
§2.3Method 3: Use A4 Paper
The third method removes the problem from the printing side. People in North America who often need to print international documents can buy paper in the A4 size. The memo says A4 is available in the United States from many large paper distribution companies, and that almost all laser printers support it.
Nothing in the memo requires a change to the document itself, so this is the simplest route when the volume of international printing is high enough to justify keeping a second paper size in the office.
Print on A4 paper instead. A4 is sold in the United States by the large paper distributors, and almost all laser printers can take it. Nothing has to change in the document, so this works well when international printing is frequent.
§4Security Considerations
The memo's security section is short and pointed. Following the recommendations makes a document more likely to be readable and to look the same to every recipient, which reduces the risk of misunderstanding. The recommendation introduces no known new security risk of its own. The memo does warn of a different kind of mistake: relying on the recommendations might make some writers too confident that their documents will look identical everywhere.
It also notes that PostScript has well-known security risks, and refers the reader to RFC 2046 for the discussion of them. The memo's own security advice is therefore about reading and appearance rather than about the file format's behaviour.
Following the advice makes a document look the same for everyone who prints it, which reduces misunderstandings, and it adds no new risk of its own. The one real security point is that PostScript is known to be risky, and the memo points to RFC 2046 for that discussion.