Type size equivalents between 号 and "point"

[ryukeikun]

For section 2.3.5 Considerations when Designing the Type Area | 版心设计的注意事项 | 版心設計的注意事項, the values for 号 and "point" have 2 issues:

1. there are more 号s in actual usage, e.g. in Microsoft Word (Chinese version) font list, there are
   大特号 (=63 pt)
   特号 (=54 pt)
   etc

2. the conversions between hao 号 and point (American point or DTP point, that's another question, though) are actually not unified yet, e.g. in Microsoft Word (Chinese version),

二号=22pt but not 21pt,
三号=16pt but not 15.75pt、
四号=14pt but not 13.75pt,
六号=7.5 pt but not 7.875pt、
七号=5.5 pt but not 5.25pt.

In hot metal era, the type size are also different from different type foundries. See the values shown in the book below, it just showed one of the variations. Some of the values go with Word, some of them not.

Although widely used, the settings of Microsoft Word are not correct due to its spec: the value of type size "should in multiples of .5 (such as 10.5 or 105.5)" (see https://support.office.com/en-us/article/Change-the-font-size-931e064e-f99f-4ba4-a1bf-8047a35552be?ui=en-US&rs=en-US&ad=US) so Word cannot set 三号 as 15.75 pt but 16pt.

How should we do such differences?

[ryukeikun]

建议此段修改如下：

中文活字大小有不同单位。在金属活字时代，传统中文活字尺寸以「号」为单位，故称作「字号」；在照相排版时代沿用照排机尺寸的单位「级」，故称作「字级」；在桌面排版时代，直接使用桌面排版软件中的「点」（DTP point）。目前，很多场合的中文排版依旧习惯沿用「号」。

「号」由于当年金属活字各地厂家的规范不一而不尽相同，「号」也有英美、欧陆、DTP等多种制式，导致「号」与「点」的换算有不同方法。下表仅列出常见的一些换算数值，仅供参考，不作为规范性规定：

号数	点数
初号	42 pt
一号	27.5/28 pt
小一号	24 pt
二号	21/22 pt
小二号	18 pt
三号	15.75/16 pt
四号	13.75/14 pt
小四号	12 pt
五号	10.5 pt
小五号	9 pt
六号	7.875/8 pt
七号	5.25 pt

[huijing]

我试试看做个英文翻译，但是有些词不知道怎么翻，要大家帮个忙。文档里的table我已经在自己的branch修改了。

There have been different size systems for Chinese characters. The traditional size system used for metal typesetting utilised numerical units. During the phototypesetting era, 级 were used as the sizing units instead. When it came to desktop publishing, font sizes were determined by the DTP point system which was built into the software itself. Currently, the traditional numerical units are still used for typesetting in many Chinese publications.

These numerical units were not standardised by the various foundries in the past. In addition, there were also differing systems based on the Americas, Europe, DTP and so on, which resulted in numerous conversion methods between numerical units and point measurements. The following table lists unit values and their most common corresponding conversions as a reference. It is not meant to be a standard.

[ryukeikun]

建议「号」就用 hào (literally No. ) 而「级」应该是 Q；另外我原文有一个笔误，『「号」也有英美、欧陆、DTP等多种制式』→『「点」也有英美、欧陆、DTP等多种制式』。

建议修改如下，大家觉得如何？

There have been different size systems for Chinese characters. The size system in traditional metal type utilized hào (literally No. ) units, while in the phototypesetting era, Q were used as the sizing units instead. When it came to desktop publishing, font sizes were determined by the DTP point system which was built into the software itself. Currently, the traditional hào-system are still used for typesetting in many Chinese publications.

These hào-system were not standardized by the various foundries in the past. In addition, point-systems were also different in Anglo-Americas, Europe Continental, DTP and so on, which resulted in numerous conversion methods between hào-system and point-system. The following table lists their most common corresponding conversions as a reference. It is not normative information.

[macnmm]

I would guess that the 級 and 歯 units from photo typesetting are mm-based? In Japan this is what they are, and we have similar confusing issues with Points being either American Point, JIS Point, DTP point, Didot Point or Traditional Point, all different. 号 units also differed by foundry, I believe, and conversion tables used either Traditional Points or JIS Points, and needed conversion to DTP Points to be usable in software. Anyway, complex topic.