Fontmake is a tool to generate font binaries. Run fontmake --help to see all the options.
Fontmake makes use of a variety of Python libraries to build TTF fonts from UFO or Glyphs source files:
.glyphs files into UFO format;You don’t have to understand this very well to start working with the tools, but it can come in handy if you have a bug to report, or if you want to understand the relationship between the different libraries. See “What happens when you build a variable font (using the open source tool chain)” for more details.
Unfortunately, Fontmake is not enough to generate fonts that can be onboarded to Google Fonts. Some post-processing is needed to meet Google Fonts requirements. The gftools scripts are an enhanced collection of helpers to do that post-processing.
Run gftools --help to see the available scripts.
These scripts are extremely useful to batch patch binaries (as well as UFO).
You can use for example gftools gen-stat to easily patch a STAT table to your variable font:
gftools gen-stat path/to/*.ttf --src stat.yaml --inplace
--inplace would be to override the font files, --src would be to use an external yaml file with axis values instructions, for example:
# stat.yaml
- name: Width
tag: wdth
values:
- name: Condensed
value: 75
- name: Normal
value: 100
- name: Weight
tag: wght
values:
- name: Regular
value: 400
linkedValue: 700
flags: 2
- name: Bold
value: 700
If you need to patch a different STAT table on separated fonts of the same family—for example in the case of Italic—you can add file name information, such as:
# stat.yaml
Fontname[wght].ttf:
- name: Weight
tag: wght
values:
- name: Regular
value: 400
flags: 2
- name: Italic
tag: ital
- name: Regular
value: 0
linkedValue: 1
flags: 2
Fontname-Italic[wght].ttf:
- name: Weight
tag: wght
values:
- name: Regular
value: 400
- name: Italic
tag: ital
- name: Italic
value: 1
Google Fonts has a policy of building all exports in one step to simplify the font generation process. To generate the font with Fontmake, and then post-process the binaries with some gftools scripts, users often created a bash shell script.
Example: Public Sans
As you can see in the example, these build scripts were extremely long and redundant. That is why gftools builder was created.
gftools builder is a command line tool that wraps Fontmake to efficiently generate several font formats in one command, as well as several gftools fix-* and gftools gen-stat scripts to post-process the generated fonts following Google Fonts’ specifications.
Run gftools builder --help to see all the options.
The Builder can take source files (.glyphs, .ufo, .designspace) as direct argument.
You can do that if:
Example:
gftools builder FontName.glyphs FontName-italic.glyphs
This will generate Static OTF, TTF, WOFF2 and Variable TTF, using the Axis Registry to set up the STAT table.
Using a yaml file with more detailed instructions is a preferred option to have more control over the outcome. Once this “config” file is set up, you would just have to run, for example:
gftools builder config.yaml
For Example: JetBrains Mono
# config.yaml
sources:
- FontName[axis].glyphs
- FontName-Italic[axis].glyphs
axisOrder:
- wght
- ital
familyName: "Font Name"
Google Fonts only needs TTF fonts, so you can avoid building OTF as well by adding:
buildOTF: false
→ Note that the ital axis shouldn’t be in the source files if the Roman is separated for from the Italic. Although, the axis order is here to describe the entire design space of the family, so the ital should be mentioned to properly set up the style linking between the two files, as well as a complete STAT table.
For example: Texturina, Montserrat, Roboto Serif.
If there is a non-registered axis or there is an Optical Size axis, you would have to detail the STAT table information because, in that case, the Axis Registry can’t be used:
sources:
- FontName[opsz,wght].glyphs
- FontName-Italic[opsz,wght].glyphs
axisOrder:
- opsz
- wght
- ital
FamilyName: "Font Name"
stat:
FontName[opsz,wght].ttf:
- name: Optical size
tag: opsz
values:
- name: 12pt
value: 12
- ...
- name: Weight
tag: wght
values:
- name: Regular
value: 400
linkedValue: 700
flags: 2
- ...
- name: Bold
value: 700
- name: Italic
tag: ital
values:
- name: Roman
value: 0
linkedValue: 1
flags: 2
FontName-Italic[opsz,wght].ttf:
- name: Optical size
tag: opsz
values:
- name: 12pt
value: 12
- ...
- name: Weight
tag: wght
values:
- name: Regular
value: 400
linkedValue: 700
flags: 2
- ...
- name: Bold
value: 700
- name: Italic
tag: ital
values:
- name: Italic
value: 1
If you want a STAT table format 2 (min and max ranges) your axis value should look like this:
stat:
- name: Width
tag: wdth
values:
- name: Condensed
rangeMinValue: 40
nominalValue: 50
rangeMaxValue: 75
...
If you want a STAT table format 4 (multi axes) you should add this after defining the axes, at the same level as the “normal” stat definition:
stat:
…
statFormat4:
- name: Green
location:
wght: 300
wdth: 200
- name: Blue
location:
wght: 400
wdth: 200
If there is a VTT manual hinting program you should add this to this example:
vttSources:
FontName[opsz,wght].ttf: VTT/roman-hinting.ttx
FontName-Italic[opsz,wght].ttf: VTT/italic-hinting.ttx
If you want to set up static instances, different from the one set up in your .designspace file or in your .glyphs sources:
instances:
FontName[opsz,wght].ttf:
- familyName: "FontName 8pt"
styleName: "Regular"
coordinates:
opsz: 8
wght: 400
- familyName: "FontName 8pt"
styleName: "Medium"
coordinates:
opsz: 8
wght: 500
Unfortunately, the Builder can’t do everything yet. You will have to use an external bash script in these cases:
WOFF. use homebrew webfont tools..glyphs, .glyphspackage, and .ufo: the build script should contain a step that converts the sources to UFO. Use Fontlab to UFO or FontForge to UFO for example.