Adding glyphs to an existing commercial font

Hello everybody!

I would like to add a few glyphs, such as Ḇ ḇ Ḍ ḍ Ǧ ǧ Ḥ ḥ Ḫ ḫ etc., to an existing commercial font family (only for personal use).
Is GlyphsMini enough to perform only this task or would I need to purchase the full app Glyphs?

One more question: when I do so, are the changes automatically applied to all weights, styles and optical designs of that font family?
Let’s say, for example, I want to add the glyph Ṛ (Latin capital letter R with dot below) to the Adobe Jenson Pro.
I open Jenson Pro regular,
I copy the capital letter R,
I copy the dot from some other glyph,
then I merge the R with the dot and I obtain the glyph Ṛ, which I will save in the appropriate Unicode block and code point.
Now… are the changes also applied to Jenson Pro Bold, Jenson Pro Italic, Jenson Caption, etc. or would I need to modify individually each style?

Thank you

You can do that in both versions. If the font relies on OpenType features, you might lose some of them in Glyphs Mini.

Glyphs Mini can only work on a single master at a time.

A font family consists of one file for each weight. If you work on each file, that means you will have to do it over and over again, unless you can reconstruct a multiple-master setup. To do that, it may be better to obtain the original design files.

Thanks to the both of you. It seems to be a difficult work, I don’t know if I can make it.

That is not as difficult as it sounds. You can try it for free in both apps.

Hello again!

I have downloaded and installed the trial app GlyphsMini. Creating all the missing diacritics was easy, I successfully added all the glyphs I wanted (ḍ, ǧ, etc.) to the Adobe Jenson Pro regular (of course I worked on a duplicated file). As expected, when I exported the font I lost the OpenType features (the alternative long-swash capital Q, the old-style numbers, discretionary ligatures, etc.).
Is there a way to keep those features? Would it be possible with the full version of Glyphs (not the ”mini”)?
If it isn’t possible to keep them, I thought I could use the original Jenson Pro and my modified version together in the same text block, but I have discovered that in my modified version the leading had changed (much more space among lines), so the leading becomes inconsistent through the page.
Why this happened? Is there a way I can adjust the leading of my modified font to make it perfectly match with the original font?

All this you can do in the full version.

You might need to reimport the original .otf go get the OpenType features and the original vertical metrics.

Thank you.

Any idea about why the leading has changed?

I’ve made this test, just to be sure the problems didn’t come from the diacritics.

I started again from zero, from an original Jenson Regular OpenType .otf font by Adobe.
I opened this file (let’s call it A) with GlyphsMini, just to create a glyph file I could work with, but I immediately select Export, to generate a new .otf font (let’s call it B).
Now… B should be identical to A, since I left everything untouched (no new letters were added, nothing at all).
Actually if I try to use font A and font B in the same text document, they don’t look metrically compatible. B seems to ask for some extra room above the letters and that makes the the leading inconsistent.

How could this happen and how could I fix it?

No. It is very unlikely that compiling with one software (which already loses some information) yields the exact same binary as reverse-engineering (not everything can be reconstructed, so some information will be lost again) and recompiling it with a different software.

You will have to reconstruct the vertical metrics. There is a tutorial about that in the Tutorials section. Sorry I cannot spare you the digging deeper.

So it would be more convenient if I succeeded to keep the OpenType features in my modified font (with diacritics, etc.) and completely dismiss the original font, right? I mean… instead of mixing the two fonts in the same documents.

Are we sure with the full Glyph app I will be able to keep (or somehow restore) all those OpenType features?
I need stuff like old-style numbers, fractions, discretionary ligatures, small caps, but, at the same time, I need all the new glyphs with diacritics, which are missing in the original font.

I’m a totally beginner at using font design programs, what would you do if you were at my place?

You can try that yourself, there is a trial version, too.

There are many ways to define vertical metrics. Glyphs Mini picks one of them. That means that some fonts have different vertical metrics when opening/exporting them. If you open the same original file in Glyphs, you’ll see a bunch of ‘custom parameters’ in the masters settings. That are all the vertical metrics values.

Thank you!

When I open a font with GlyphsMini i can only see a brief info panel showing Horizontal Stems, Vertical Stems, Alignment Zones and few other things. Even if I keep the same identical values, the font will not look the same after I export it.
I guess Glyph full application has many more parameters.
If I move to Glyphs full version and I copy all those custom settings, will I be sure the exported file will be metrically compatible with the original commercial font?
Or would it be easier to restore all the OpenType features, so that the new font will be “complete” and I can use it as my only font?

I just explained that Mini is using default values that usually work well with most fonts. But that most likely doesn’t match an exiting font. But the full version can deal with that and in your case you’d really need the full version.

Read this:

Thank you, useful document, now I understand a bit better.
Is there a way I can obtain somewhere the original VFB or UFO files?
I suppose the original publishers / foundries (Adobe, in this particular case) keep them secret…

Some are open source, actually, but not this one, I am afraid.

When I open an existing commercial font in GlyphsMini, I usually find two identical sets of glyphs for small caps. For example, there are both a and a and they seem to be pretty much the same. Is one of them redundant? May I delete it? And which one should I delete and which should I keep?

That was a practice for improving character string reconstruction when a user selected and copied text in a PDF. Without it you would receive mixed upper and lowercase more often. Copying text out of PDFs has so many other problems though that keeping two separate SC sets seems like beating a dead horse. I do not recommend it anymore.