1# Print Reftests
2
3Print reftests are like ordinary [reftests](reftests), except that the
4output is rendered to pagninated form and then compared page-by-page
5with the reference.
6
7Print reftests are distinguished by the string `-print` in the
8filename immediately before the extension, or by being under a
9directory named `print`. Examples:
10
11- `css/css-foo/bar-print.html` is a print reftest
12- `css/css-foo/print/bar.html` is a print reftest
13- `css/css-foo/bar-print-001.html` is **not** a print reftest
14
15
16Like ordinary reftests, the reference is specified using a `<link
17rel=match>` element.
18
19The default page size for print reftests is 12.7 cm by 7.62 cm (5
20inches by 3 inches).
21
22All the features of ordinary reftests also work with print reftests
23including [fuzzy matching](reftests.html#fuzzy-matching). Any fuzzy
24specifier applies to each image comparison performed i.e. separately
25for each page.
26
27## Page Ranges
28
29In some cases it may be desirable to only compare a subset of the
30output pages in the reftest. This is possible using
31```
32<meta name=reftest-pages content=[range-specifier]>
33```
34Where a range specifier has the form
35```
36range-specifier = <specifier-item> ["," <specifier-item>]*
37specifier-item = <int> | <int>? "-" <int>?
38```
39
40For example to specify rendering pages 1 and 2, 4, 6 and 7, and 9 and
4110 of a 10 page page document one could write:
42
43```
44<meta name=reftest-pages content="-2,4,6,7,9-">
45```
46