In glyph: .notdef Master is outside of the interpolation space at 72... error on Export VF

I have a font with three axes: Width, Weight, and Optical Size.

When I tried to export the master, I encountered an error related to the .notdef glyph (I haven’t set a custom .notdef glyph in my font).

The opsz axis is defined only for the Thin weight, not for the others.

This might be causing the issue.
Should I define the opsz axis for every Width and Weight variation as well?

According to Microsoft documentation, my opsz axis ranges from 14 to 72, with 72 being the maximum and 6 being the minimum.

I’ve attached an image of my settings below.

P.S. I have read the other issues related to the .notdef glyphs, and I have not found a real solution. Sorry in advance if I misunderstood the other answers.

Thank you in advance for your help!


hi thierry, nice to see you here :slight_smile:
yes, every master needs a location for every axis
you probably need 18 masters for the setup your are envisioning
though based on the “a” in the preview I doubt a font like this needs an optical axis

1 Like

Hello Jeremy,

It’s nice to see you there too! How are you?

Regarding the optical size, it might not be used as you expected, but it can be useful for my purpose. It is clearly an experiment. I will give you a clue… it’s in the name of the font. I will keep you posted if you are interested when I have further tests done on my side. Thank you so much for your help with this one.


Side note: the .notdef is just the first glyph processed. Anything fishy in the setup will manifest itself with that glyph.

1 Like

Thank you Rainer Erich for your side note. That’s what I suspected. Do I need to add a custom .notdef, or does it not matter at all (though it is a good practice)?


The problem is not the notdef, but your setup. The notdef is simply the first glyph that is processed, so it will be the first (and thus only) one to trigger an export error.

You cannot have only one master at a different opsz location, as Jeremy already pointed out.

1 Like

I am encountering this error as well when I want to set some of the default values to be in the middle.

Say for a 3-axis setup and I want the default master at the exact centre, the bare minimum of masters I want are these red ones and the middle one as the default, but Glyphs gives me the error. I suspect additional 18 are needed around it. Is this the case?

1 Like

That is only possible if you use one of the corners as default. The central master can be an intermediate master and you should get the desired result. Otherwise you need basically all the gray dots as masters, too.

1 Like

So, is adding all the neighbours too the only way to make the centre values as the default?

1 Like

I think so.

1 Like

I confirm, 18 Master works for me. I big thanks to every one for your Help.

But that would be a big waste. Keeping all that in sync and the file size is several times bigger than it needs to be.

Does that not mess up Adobe menus anymore by adding another Regular instance ( =origin) before all real instances?

I agree.