CSS for print tutorial

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1 Introduction

CSS 2.1 includes a few properties and an @-rule that allows for better printing. In this short tutorial we shall introduce most of that. CSS3, under the name of CSS Paged Media Module Level 3 includes much more sophisticated features for creating print documents. So far, these are not introduced in this text.

Learning goals
  • Be able to style text-centric HTML pages (e.g. articles, tutorials, novels)
Prerequisites
Level and target population
  • Beginners
Teaching materials
Remarks
  • This tutorial is intended for students in educational technology or any other field that is technology intensive. For people who need less, there exist many easy CSS tutorials on the web. This text is intended for students who also must learn principles and who are willing to learn CSS by doing a project, looking at CSS code and online reference manuals.
  • Ideally, a teacher also should assign a text formatting task, during or before assigning this tutorial for reading).

2 Linking styles for printing

As explained in the CSS media and alternative style sheets tutorial, there are three ways for defining alternative styles:

(1) Use @media rules in a stylesheet

@media print body {
	font-family: "Palatino Linotype", "Book Antiqua", Palatino, serif;
	font-size: 1em;
	color: #333333;
	margin-top: 2cm;
	margin-right: 2cm;
	margin-bottom: 1.5cm;
	margin-left: 2cm
        }

(2) Define an alternative stylesheet in the HTML

Most web designs probably prefer this solution.
<link rel="stylesheet" href="print-style.css" type="text/css" media="print" />

(3) Define an alternative stylesheet in the CSS

The @import at-rule allows to specify a media type, i.e. you may use this strategy to load various CSS variants from a single CSS file or within a HTML script section.
Inside a CSS file:
@import url(print-style.css) print;
Inside an HTML file
<style type="text/css">
@import url(print-style.css) print;
</style>

3 Adapt styles for printing (minimal solution)

Most often, you will have to do the following:

(1) Remove unwanted items, e.g.

 #navigation, .do-not-print, #menu {display:none}
Of course, you will have to adapt this to your CSS. #navigation is an example of an element ID and .do-not-print an example of a class.

(2) Contents should not float and width should be set to 100% or auto

  • Remove :floats
  • Set width's back to 100%

(3) Contrasts should be optimized for a printer.

E.g. text should be black and the background should be white, or at least print ok on a printer with grey levels.

Simple minimalistic example

Taken from CSS Design: Going to Print by Eric Meyer, May 2002:

body { background: white; }

#menu { display: none; }
 
#wrapper, #content {
 width: auto;
 border: 0;
 margin: 0 5%;
 padding: 0;
 float: none !important;
 }

In addition, you could print out URLs like this:

a[href^="http://"]:after, a[href^="ftp://"]:after {
  content: " (" attr(href) ")";
  color: blue;
  font-size: small;
}

4 Using CSS 2.1 pagination

4.1 @Page rule

Instead of defining margins, you can use the @page directive. “Authors can specify the margins of a page box inside an @page rule. An @page rule consists of the keyword "@page", followed by an optional page selector, followed by a block containing declarations and at-rules. Comments and white space are allowed, but optional, between the @page token and the page selector and between the page selector and the block. The declarations in an @page rule are said to be in the page context.” (Paged media, CSS 2.1 Specification]

The @page rule takes an optional pseudo-selector for first, left, and right pages. You then can define margins. However, you can't use px and pt's since these are useless units for a printer. Examples:

/* Default left, right, top, bottom margin is 2cm */
@page { margin: 2cm } 

/* First page, 10 cm margin on top */
@page :first {
  margin-top: 10cm;
}

/* Left pages, a wider margin on the left */
@page :left {
  margin-left: 3cm;
  margin-right: 2cm;
}

@page :right {
  margin-left: 2cm;
  margin-right: 3cm;
}

4.2 Page breaks

You should specify when page breaks must occur and when they should not occur. Modern browsers implement three CSS constructs: page-break-before, page-break-after, page-break-inside, orphans and widows.

  • page-break-before and page-break-after take the following values: auto, always, avoid, left, right and inherit
  • page-break-inside can be avoid, auto or inherit
  • orphans and widows, is a number (e.g. 2)

Note that these are recommendations, i.e. a browser generating the print document should but must not use these heuristics:

  • Break as few times as possible.
  • Make all pages that do not end with a forced break appear to have about the same height.
  • Avoid breaking inside a replaced element.

Below are some typical use cases.

page-break-before
defines if page breaks should occur before the tag, typically titles
Example
 section {page-break-before: always;}
 h1 {page-break-before: always;}
page-break-after
defines if page breaks should occur after a tag
 section {page-break-after: always;}
 h1 {page-break-after: avoid;}
page-break-inside
defines if page breaks should occur inside an element.
 p {page-break-inside: avoid;}
orphans and widows
CSS 2.1 also allows to specify what happens with orphans and widows. “The 'orphans' property specifies the minimum number of lines in a block container that must be left at the bottom of a page. The 'widows' property specifies the minimum number of lines in a block container that must be left at the top of a page. Examples of how they are used to control page breaks are given below.” (from the specs
Example
 p {orphans:3; widows:2;}

5 CSS3 Multiple columns

While multiple columns can make sense on web page styles that aim at larger screens - in the CSS media and alternative style sheets tutorial‎‎ we explain how to target wide screen areas- it makes a lot of sense when printing on A4 or US letter paper. CSS3, in the CSS Multi-column Layout Module offers the possibility to define multiple columns in a quite flexible way.

Details need to be written, search for a tutorial on the web or see the specification ...

Example code:

body { 
     column-count: 2;
     column-gap: 2em;
     column-rule: thin solid black;
 }

/* This would create an h1 title that spans across the page */
h1 { 
  column-span: all 
  break-before: column; 
  break-inside: avoid-column; 
  break-after: avoid-column;
}

Support for this module, is so far quite bad. However, experimental proprietary extensions do work as of spring 2013, e.g.

-moz-column-count:3; /* Firefox */
-webkit-column-count:3; /* Safari and Chrome */

6 Simple example

Print this or better just "preview print" in order to see the stylesheet effect.

Highlights from the HTML code:

<link rel="stylesheet" href="just-so-stories.css" type="text/css">
<link rel="stylesheet" href="just-so-stories-print.css" type="text/css" media="print">
.........
<p class="noprint"><a href="#copyright">Copyright information</a></p>
.........
<h2 class="noprint">Copyright Information</h2>

"Highlights" from the print CSS:

/* ------- Pagination */

h1, h2 {
    page-break-after: avoid;
    page-break-before: always;
}

p {
      orphans:3;
      widows:3;
}

.noprint, pre.copyright {
     display:none;
 }

Disclaimer: Rendering of this example could be improved in many ways. I just teach some CSS, I don't do websites :) - Daniel K. Schneider (talk) 19:00, 6 May 2013 (CEST)

7 Links

Specifications
  • Paged media Chapter 13 for CSS 2.1. This should work with all modern browsers as of 2013.
  • CSS Paged Media Module Level 3, W3C Working Draft 14 March 2013 (as of May 2013). May not work well in current browsers since this is not standard yet.
  • CSS Print Profile, W3C Working Group Note 14 March 2013 (as of May 2013). Quote: “ This specification defines a subset of Cascading Style Sheets Level 2, revision 1 [CSS21] and CSS Paged Media Level 3 [PAGEMEDIA] for printing to low-cost devices. It is designed for printing in situations where it is not feasible or desirable to install a printer-specific driver, and for situations were some variability in the output is acceptable.”
  • CSS Multi-column Layout Module, W3C Candidate Recommendation 12 April 2011 as of May 2013. Should work fairly well in all browsers. However, you may have to use browser-specific property names since this is not a standard yet.
Other tutorials