Developing fonts > Tools & SDKs > VOLT
VOLT and InDesign Tutorial
Step 4 - Adding old style numerals
Old style numerals (or figures) — the more traditional sort of numerals which are sometimes referred to as 'lowercase' —
have long been a problem in digital typography. Most fonts simply didn't provide the option of old style figures, while the
ones that did usually came with lining (full capital height) figures, with the old style in an auxillary (or 'expert') font.
Though old style numerals are preferred in fine text typography for their elegance and more harmonious appearance, with
surrounding letters, easy access to them has long been problematic.
Now, with a properly done OpenType font, typographers can have seamless access to both lining and old style numerals (by simply
toggling the 'Old Style' menu option in InDesign). To add support for this feature, we will use the OpenType layout
Creating the glyph groups
As with small caps, creating glyph groups for this feature will be useful: again, we are simply substituting one set of glyphs
for another. However, since we're now familiar with the glyph group concept, this time we can take a small short cut. Instead of
specifying each glyph in the group individually on its own line, we can use VOLT's ability to specify a range of glyphs with
square brackets ([ and ]).
First, we'll add the lining numerals group (which will be replaced by the old style group when the 'Old Style Numerals' feature
is turned on in InDesign). Add a new group, just as we've done before, and name it something like 'lining_numerals'. Then, in
the group editing window, we'll input the range of glyphs for the group. In the 'Edit Glyphs' window, find the glyph name of
your first lining numeral ('0') and the glyph name of the last one ('9'). Then, in the first line of group editing window, type:
[glyph_name_0 - glyph_name_9]
and replace the two glyph names with the corresponding names in your font. After hitting ENTER, your window should look
something like this:
Next, create another glyph group (named something like 'os_numerals') for the old style figures, again specifying the 0 to 9 range.
Creating the 'onum' feature and associated lookup
Once both groups are created, we can add the <onum> feature — highlight the 'Default' language and
click the 'Add Feature' button. Type in <onum> and hit ENTER. VOLT will label the new feature 'Old Style Numerals'.
For the final step, we must create the lookup that will perform the substitution, and then link it to the <onum>
feature we created.
Click the 'Add Substitution' button and name the new lookup something like 'old_style'. In the edit window, type:
<lining_numerals> -> <os_numerals>
and hit ENTER. Returning to the main VOLT window, click the 'old_style' lookup we've created and drag it to the
'Old Style Numerals' feature in the scripts/languages pane. The old style numerals layout feature is now complete.
Next section: Step 5 - Adding case-sensitive featuresintro | start | ligatures | small caps | numerals | case | compiling | InDesign
Last updated 19 August 2000.
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