Re: Towards some more Private Use Area code points for ligatures

From: William Overington (
Date: Fri May 31 2002 - 04:01:02 EDT

Michael Everson wrote as follows.

>At 11:24 +0100 2002-05-30, William Overington wrote:
>>I am also having a look at the idea of having code points for the famous
>>combination border of the type used by Robert Granjon in the sixteenth
>Code points are assigned to characters. Even in the PUA, it would be
>advisable to keep to the character-glyph model.
>Michael Everson *** Everson Typography ***

I am not sure that I understand what you mean. Does the following explain
satisfactorily or am I missing some other aspect of the matter?

In metal type, in the Monotype version, the Granjon combination border
consisted of six sorts.

Three were 24 points square. There are two which are mirror images of each
other and one which is different entirely. The two have a "going round"
look as almost quarter circles as large as possible, narrow at one end, wide
at the other, the circle centred on one of the corners of the piece of
metal. The different piece has a look of going from narrow to wide
diagonally from one corner to another. This is not a full description which
would allow someone to draw accurate depictions of the sorts, yet are, I
feel, sufficient for people who know the Granjon design to recognize the
pieces, so that going from narrow to wide clockwise or going from narrow to
wide counterclockwise clearly distinguishes which pieces I mean.

These three sorts can be each placed in four orientations and, with care,
combined effects of various kinds can be produced. These combined effects
often consist of joining together 48 point by 48 point blocks, each block
usually consisting of either two of each kind of the "going round" sorts, or
four of the other sort. Various designs of blocks can be produced.

The combined effect need not be just borders. Panels of designs can be

Two were 24 points by 21 points. They are mirror images of each other.
They have the look of a vaguely circular shape in one end of the surface
area of the piece of type, with pommels on one side of the circle, that is
the pommels are adjacent to a 24 point long edge..

One was 24 points by 6 points. This is what I have called the bar. It is
its own mirror image with a wider central line and a fine line each side, up
the length of the bar.

Now, in order to use this effectively from a TrueType fount, in, say 24
point, though, as TrueType can be displayed in any size, 24 point is here
just as an example, my thinking is that all of the sorts available need to
be on a 24 point body, and upright. So, my idea is that each of the items
which, in metal type, are 24 points square, would be encoded as four private
use area code points, one for each possible orientation, making a total of
12 code points. The other pieces would then be supplied in 24 points as
well, as they stand, and also as the two pieces which are 24 points by 21
points upside down. The bar does not need to be supplied upside down as it
is vertically symmetrical as well as horizontally symmetrical.

Now, in order that more of the full possibilities of the combination border
may be used, though not entirely all, I have devised a virtual type unit
which is 24 points by 24 points consisting of a 24 points by 21 points piece
glued onto a 24 points by 3 points half width slice of a bar piece. The
constructing of such a virtual type unit can be achieved in four ways,
depending on which of the 24 point by 21 point pieces is used and which way
up it is used. Each of the four virtual type units can be displayed in four
orientations, which means that 16 code points are allocated to them.

William Overington

31 May 2002

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