Hello,

I’d like to make old style fractions. I can add glyphs like onehalf.osf etc. this is simple, but:

- what about fractions generated by frac feature (8/9) ?
- ascending figures like 6 and 8 could use normal fractions
- x-height figures like 0,1,2 should have their own x-height fractions
- descending figures 3,4,5,7,9 could use normal fractions with offset

What do You think about this?

How do osf fractions look like?

I’ve never seen such fractions.

I read in a book “Book Typography: A Designer’s Manual” that fractions near old style figures should be minimized if they seems to large.

So I think: isn’t it possible with OT features?

So I could make an additional set of numerators and denominators - one.numr.osf etc. and fraction.osf that would be a little bit smaller to harmonize with lowercase glyphs.

Than some changes to the frac feature should be made. And my question is what changes?

Ok. I did it.

It turned out to be very simple. I just added old style glyphs (numerators, denominators, fraction.osf and slash.osf) and hit refresh button on onum feature. Than I made some changes to the frac feature:

lookup FRAC {

sub** [slash slash.osf] by [fraction fraction.osf] **;

} FRAC;

lookup HOCH {

sub [zero one two three four five six seven eight nine] by [zero.numr one.numr two.numr three.numr four.numr five.numr six.numr seven.numr eight.numr nine.numr];

} HOCH;

lookup TIEF {

sub **[fraction fraction.osf]** [zero.numr one.numr two.numr three.numr four.numr five.numr six.numr seven.numr eight.numr nine.numr]’ by [zero.dnom one.dnom two.dnom three.dnom four.dnom five.dnom six.dnom seven.dnom eight.dnom nine.dnom];

sub [zero.dnom one.dnom two.dnom three.dnom four.dnom five.dnom six.dnom seven.dnom eight.dnom nine.dnom] [zero.numr one.numr two.numr three.numr four.numr five.numr six.numr seven.numr eight.numr nine.numr]’ by [zero.dnom one.dnom two.dnom three.dnom four.dnom five.dnom six.dnom seven.dnom eight.dnom nine.dnom];

} TIEF;

for now it seems to be working.

ahhhhhh there is no need to change frac feature.

just add new glyphs and refresh onum