Re: Specifying the vertical positioning of the kihon-hanmen

Hi Martin,

Thanks for your helpful reply.  Unfortunately, these days I don't have W3C
member access, but, apart from one detail, I think I now understand.

Suppose I take an A3 sheet of paper and fold it three times, so that I have
an A6-sized booklet with 16 pages.  Of the two shorter edges of the
booklet, one edge will have pages that are all open (next to the outer edge
of the A3 sheet of paper) and one edge will have pages next to a fold.  In
Western printing I believe it would be arranged so that when the long
binding edge is on the left, the short top edge would be next to the fold
(and the bottom edge would be open).  If I rotate a booklet so arranged 180
degrees around the center of the page, so that the binding edge is on the
right, then the edge next to the fold which had previously been on the top
will now be on the bottom.  So I understand the concept of how changing
from left- to right-side binding swaps the top and bottom.  Thus in both
the horizontal and vertical books, the vertical margin that is specified is
consistently the one next to the fold. The detail I don't understand is why
this is desirable.  In other words, why is the vertical margin that you
want to specify the one next to the fold?

In traditional Western printing, there is actually a good reason
historically why the margin next to the fold is the top margin.  The reason
is that it used often to be the case that only one edge would be trimmed,
which would be the edge next to the folds (the remaining folds on the outer
edges are easily cut by the reader with a paper knife as they read the
book).  But it's better for the top edge of the book to be trimmed one,
because having a solid, cut edge on top helps stop dust getting into the
book when it is sitting on a bookshelf.

James


On Tue, Jan 21, 2014 at 4:42 PM, "Martin J. Dürst"
<duerst@it.aoyama.ac.jp>wrote:

> Hello James,
>
>
> On 2014/01/21 12:14, James Clark wrote:
>
>> Before I ask my question, I just wanted to say thank you to everybody
>> involved in producing the "Requirements for Japanese Text Layout" note.
>> It is an extraordinarily interesting and helpful document.
>>
>> The note says [1] that the vertical position of the kihon-hanmen relative
>> to the trim size is either centered or specified using the head (ie
>> top-margin), for horizontal mode, or foot (ie bottom margin) for vertical
>> writing mode.
>>
>> I am puzzled by the vertical writing mode case.  Given that the inline
>> progression direction is top-to-bottom, what is the logic for specifying
>> the bottom rather than the top margin in this case?  Do you specify the
>> bottom margin even if you have horizontal rather than vertical running
>> heads/foots?
>>
>
> This is a very good question Makoto (MURATA) forwarded it to the
> member-japanese-layout-ja@w3.org mailing list.
>
> Toshi Kobayashi, one of the core members of the Japanese Layout Taskforce,
> sent a detailed reply in Japanese. Those who have W3C Member acces can view
> it at https://lists.w3.org/Archives/Member/member-japanese-layout-
> ja/2014Jan/0001.html. Even if you don't understand, I recommend to have a
> look at the images in the attachment.
>
> As explained by Mr. Kobayashi, this goes back to paper publishing. When
> creating a book, a number of pages (in Japan usually 16) are printed on a
> big sheet of paper in such a way that when that paper is folded and then
> cut up, the pages end up in the right order.
>
> Exactly the same process is followed for both horizontally and vertically
> printed books to avoid confusion. But because the page order in vertically
> printed books is from right to left, and in horizontally printed books,
> it's from left to right, what's "exactly the same" in terms of folding
> topology ends up to be on other ends (top vs. bottom) of the finished page.
>
> So the top/bottom change has little if anything to do with what's on the
> page, and all with the direction the pages are numbered.
>
> This is only a summary of Mr. Kobayashi's mail, but it should capture the
> essence.
>
> Regards,   Martin.
>
>
>
>
>
>  James
>>
>> [1] http://www.w3.org/TR/jlreq/#procedure_for_defining_the_kihonhanmen at
>>
>>