Crissov
commented
4 years ago PS: For consistence, I should probably also be proposing standard envelope sizes besides the generic C (and B) series, but I'm still researching this matter, e.g. which 2:1 combined formats, like C6/C5, should be considered.
| Format | Size |
|---|---|
| Invite | 220mm 220mm |
| ISO DL | 220mm 110mm |
| DL+ | 225mm 112mm |
| DL Max, Compact | 235mm 125mm |
| Italian | 230mm 110mm |
| C7/C6 | 162mm 81mm |
| ISO C6/C5, Postfix, DL+ | 229mm 114mm |
| B6/C4 | 324mm 125mm |
| E4 | 400mm 280mm |
SetTrend
This is a consolidated and updated revision of #328 from mid-2016. When @fantasai closed that issue by editor discretion, she said:
I shall show that there is specific demand for certain keywords, in the fist section below.
Moreover, although not recorded explicitly and lacking a WG decision, there appears to have been somewhat of a consensus back then that keywords should be added to CSS for
commonly used sizes with
standardized identifiers and
hard to remember dimensions.
I shall document those as well, in the second section below.
Interoperability for International Sheet and Envelope Sizes
TL;DR: Add all missing keywords for standard paper sizes in the ISO 216 A and B series, the ISO 269 C series and the JIS P 0138 B series:
A0,A1,A2andA6,A7,A8,A9,A10B0,B1,B2,B3andB6,B7,B8,B9,B10JIS-B0,JIS-B1,JIS-B2,JIS-B3andJIS-B6,JIS-B7,JIS-B8,JIS-B9,JIS-B10C0,C1,C2,C3,C4,C5,C6,C7,C8,C9,C10While web browser developers may seem less than keen to invest more resources in css-page than absolutely necessary, there are several applications specializing in CSS-driven PDF creation which strongly rely on this particular Module and may wish to extend its capabilities. The W3C should care about harmonizing their use of CSS to ease interchange and thereby making manuscripts more universal.
WeasyPrint and Vivliostyle support all currently standardized keywords for
size(orpage-sizein the future) standardized by CSS in level 3:A3,A4,A5,B4,B5,JIS-B4,JIS-B5(and AmericanLetter,Legal,Ledger). Their open source code shows that it would be ridiculously simple to add more named sizes. wkhtmltopdf uses plain headless Qt Webkit and relies on its capabilities. Addendum: paged.js seems to add all of the A series (although A8 and A9 are undocumented).Existing implementations from PDF Reactor, Prince and Antenna House support more than those specified keywords, but they use partially incompatible custom keywords for the same physical sizes. In one case, there are three different custom keywords for the same size:
ANSI-C,CandBroadsheetfor17in 22in. This hinders stylesheet interchange – avoiding this is prime motivation for standardization.However, at least two existing implementations agree on keywords and definitions of all ISO 216 formats. Since ISO paper sizes result from an irrational aspect ratio of √2:1 and an integer base area, A(A0) = 1 m², their odd edge lengths are hard to remember exactly. Their popularity, stability, ease of implementation and the difficulty of using their numeric values, makes them ideal candidates to add.
In the following table, the custom keywords already supported by implementations are highlighted if they are identical to the proposed keyword. In particular, the
ISO-prefix supported by Antenna House in aliases shall not be adopted.A1026mm 37mmA10C1028mm 40mmC10B1031mm 44mmB10A937mm 52mmA9C940mm 57mmC9B944mm 62mmB9A852mm 74mmA8C857mm 81mmC8B862mm 88mmB8A774mm 105mmA7C781mm 114mmC7B788mm 125mmB7A6105mm 148mmA6A6C6114mm 162mmC6ISO-C6B6125mm 176mmB6ISO-B6,B6A5148mm 210mmA5A5A5C5162mm 229mmC5ISO-C5B5176mm 250mmB5B5ISO-B5,B5A4210mm 297mmA4A4A4C4229mm 324mmC4ISO-C4B4250mm 353mmB4B4ISO-B4,B4A3297mm 420mmA3A3A3C3324mm 458mmC3ISO-C3B3353mm 500mmB3A2420mm 594mmA2C2458mm 648mmC2B2500mm 707mmB2A1594mm 841mmA1C1648mm 917mmC1B1707mm 1000mmB1A0841mm 1189mmA0C0917mm 1297mmC0B01000mm 1414mmB0Usability for common, standardized, odd-valued Page Sizes
TL;DR: Optionally, add keywords for the standard paper sizes in ISO 217 (raw oversizes) and ISO 5457 (untrimmed drawing paper sizes).
If the interoperability argument in the first section above was not convincing enough to add keywords for the missing sizes from ISO 216 and all of ISO 269, they should also qualify due to having standardized identifiers and odd length values, and even if some were not commonly used, it would be beneficial to add the complete series nevertheless, for consistency, so authors do not have to remember which sizes do not have a keyword in CSS.
The international standard paper sizes – series
AandBdefined in ISO 216 and seriesCin ISO 269, which has been withdrawn in 2009 but still exists in local norms like DIN 476-2 – have been adopted by many national standardization bodies. Some have extended definitions for special purposes, e.g. theRAandSRAseries from ISO 217, German2A0from DIN 476 or the now-withdrawn SwedishD–Gseries from SIS 014711 and, of course, the JapaneseBseries from JIS P 0138 that is already recognized partially by CSS. For envelopes in particular, there are also some sizes with an 2:1 aspect ratio that combine the non-common edges of two adjacent sizes, e.g. C5/C4. The respective Wikipedia article for paper size is quite comprehensive.However, most of these sizes are of limited interest to most CSS authors, at least with consumer printers, but those who need any of them would certainly welcome their addition to the standard.
Since CSS introduced the
JIS-prefix to distinguish Japanese B sizes from international ones defined by ISO, it is not surprising thatISO-,US-andANSI-also appear as prefixes for short size codes in existing implementations.Proposed side rule:
I do not propose any of those local sizes here, although some are apparently used frequently.The only local sizes I am proposing are the rest of the JIS P 0138 series. Keywords for B4 and B5 are already specified and an analogous one for B6 is already supported in at least one implementation.JIS-B1216mm 22mmJIS-B1122mm 32mmJIS-B1032mm 45mmJIS-B945mm 64mmJIS-B864mm 91mmJIS-B791mm 128mmJIS-B6128mm 182mmJIS-B6JIS-B5182mm 257mmJIS-B5JIS-B5JIS-B4257mm 364mmJIS-B4JIS-B4JIS-B3364mm 515mmJIS-B2515mm 728mmJIS-B1728mm 1030mmJIS-B01030mm 1456mmFurthermore, I propose to add all sizes from two international standards, which are not covered by the interoperability argument (as of early 2020).
ISO 217 specifies two A-based series for raw, uncut, untrimmed sheets, adding an
R(for primary range) andSR(supplementary range) prefix, respectively. PDF Reactor does support systematic keywords for all of them. The actual standard seems to only require the recognition of (S)RA0, (S)RA1 and (S)RA2, but othe oversizes to the sizes of the ISO 216 A series are encountered in practice. I think it makes sense to support at least as many sizes as the following standard for drawing paper.ISO 5457 specifies drawing paper sizes, where the trimmed sizes with a
Tsuffix are identical to the respectiveAseries sizes, whereas the sides of untrimmedUsizes are 3 to 4 centimeters larger. The standard also specifies a fixed area for the drawing space resulting from20mmand30mmpage margins, but does not assign monikers.SRA0900mm 1280mmSRA0A0U880mm 1230mmRA0860mm 1220mmRA0SRA1640mm 900mmSRA1A1U625mm 880mmRA1610mm 860mmRA1SRA2450mm 900mmSRA2A2U450mm 625mmRA2430mm 610mmRA2A3U330mm 450mmSRA3)320mm 450mmSRA3RA3)305mm 430mmRA3A4U240mm 330mmSRA4)225mm 320mmSRA4RA4)215mm 305mmRA4160mm 225mmSRA5152mm 215mmRA5112mm 160mmSRA6107mm 152mmRA680mm 112mmSRA776mm 107mmRA756mm 80mmSRA853mm 76mmRA8All American sizes, which have not already been specified in CSS, fail at least one of the three stated criteria, because their edges measure a simple number of half inches and are even often known only by those numbers (which are generally assumed to be exact).
The only popular metric sizes that are known by integer numbers are photographic prints (i.e. traditionally 9×13, 10×15, 13×18, 20×30), which, apparently, are rather approximate in fact, because they are really based on rounded inch-based specifications in ISO 1008 (see Wikipedia).