Re: RFC: remove 1-1 kerning from Adobe Palatino?

["Nelson H. F. Beebe" <beebe@math.utah.edu>]

Walter Schmidt <walter.schmidt@arcormail.de> reported to this list
on Wed, 27 Oct 1999 16:11:21 +0200 (MSZ):

>> Adobe's Palatino has one very annoying feature:
>> All digits have equal width, but there is a kerning
>> between two adjacent letters "1" defined.  As a result, 
>> tables do sometimes not align.

I was astonished at the report of such kerns, so I've been busy
searches collections of .afm files to see if there are any others that
do this.

I found such instances in 1990 versions of these Adobe files:

    Helvetica-Bold.afm                     NewCenturySchlbk-Italic.afm
    Helvetica-BoldOblique.afm              NewCenturySchlbk-Roman.afm
    Helvetica-Narrow-Bold.afm              Palatino-Bold.afm
    Helvetica-Narrow-BoldOblique.afm       Palatino-BoldItalic.afm
    Helvetica-Narrow-Oblique.afm           Palatino-Italic.afm
    Helvetica-Narrow.afm                   Palatino-Roman.afm
    Helvetica-Oblique.afm                  Times-Bold.afm
    Helvetica.afm                          Times-BoldItalic.afm
    NewCenturySchlbk-Bold.afm              Times-Italic.afm
    NewCenturySchlbk-BoldItalic.afm        Times-Roman.afm

However, when I checked 1998 releases of these files (on a new Sun
Solaris 2.7, in the directory /usr/openwin/lib/X11/fonts/F3/afm), I
found that most had had their digit kerns eliminated.  However, these
still have kerns on 1-1:

    NewCenturySchlbk-Bold.afm              Palatino-Bold.afm
    NewCenturySchlbk-BoldItalic.afm        Palatino-BoldItalic.afm
    NewCenturySchlbk-Italic.afm            Palatino-Italic.afm
    NewCenturySchlbk-Roman.afm             Palatino-Roman.afm

and those files contain "Comment Creation Date:" strings with dates in
September-October 1989.

I found no such nasty kerns in the Bitstream 500-font CD.

However, in the 2843 font Monotype 4.0 CD, I found instances of kerns
for all digits (look for these strings at beginning of line):

KPX zero
KPX one
KPX two
KPX three
KPX four
KPX five
KPX six
KPX seven
KPX eight
KPX nine

I found 710 fonts, that is, 25%, that have such kerns.  I won't
enumerate them here, but I can provide a list offline to anyone
interested.

In a collection of 86 fonts embedded in Lexmark printers, I found 16
with such kerns:

CenSchBo.afm       Helv.afm           HelvNa.afm         PalBo.afm
CenSchBoI.afm      HelvBo.afm         HelvNaBo.afm       PalBoI.afm
CenSchI.afm        HelvBoI.afm        HelvNaBoI.afm      PalI.afm
CenSchRo.afm       HelvI.afm          HelvNaI.afm        PalRo.afm
 
corresponding to CenturySchlbk, Helvetica, and Palatino families.

In the 20 Mathematica fonts from Wolfram Research, I found none.

List readers in possession of other large collections of .afm files
might wish to make further experiments: I used a UNIX command

egrep -l '^KPX +(zero|one|two|three|four|five|six|seven|eight|nine)' \
	`find . -name '*.afm' `

to get the names of .afm files with digit kerns.

In summary, kerned digits do not appear to be uncommon (note the
Monotype results), so their existence needs to be accepted.

I too am inclined to suggest that the digit kerning should be dropped
when they are accessed via TeX virtual fonts, but others may wish to
debate the issue.

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- Nelson H. F. Beebe                    Tel: +1 801 581 5254                  -
- Center for Scientific Computing       FAX: +1 801 585 1640, +1 801 581 4148 -
- University of Utah                    Internet e-mail: beebe@math.utah.edu  -
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