Font Custom Parameters

I’m trying to override autogenerated parameters in a font, say to lock the xAvgCharWidth to a certain value even if the actual value is wider, or narrower.

In looking in font info, it appears that I can do this in the Font Custom Parameters by using openTypeOS2xAvgCharWidth and setting a value there, but typing that in renders in gray rather than black. And looking in the help, only certain custom parameters are listed.

Is this to mean that only those parameters on the help page (and render in black) are available for overriding and glyphs will ignore other values set in the UFO file?

Only the black parameters are actually exported. There is no way and no cause to set the xAvgCharWidth.

Shame. I have to supply fonts with certain values locked, including xAvgCharWidth, in order to avoid compatibilities issues with applications that use the fonts.

I had hoped for a method of setting these values in the font in app and not needing to worry about it.

You can change the values afterwards using tools like ttx or OTMaster. But I have to repeat myself. These values are not to play with. They should reflect the actuall data of the font.

And I’ll repeat myself, When you’re dealing with fonts that need to be shipped with Operating Systems, and especially UI fonts that applications rely on being consistent between versions, sometimes you have to break the rules to make sure things work.

My ideal situation would be that the font generated would be ready to go, but it sounds like there will need to be manual fixes afterward in the Glyphs workflow.


Doesn’t need to be manual, can be a shell script triggered by a folder action.