I wrote this project to simplify using custom fonts with DOMPDF.

1. composer require aklump/dompdf-fonts
2. Create a directory in your project to hold the source fonts and the configuration file.
3. Copy the config file found in vendor/aklump/dompdf-fonts/dompdf-fonts.config.dist.yml to the font folder as dompdf-fonts.config.yml.

1. cd my_module
2. Install as a dev requirement: composer require --dev aklump/dompdf-fonts
3. mkdir fonts
4. cp vendor/aklump/dompdf-fonts/dompdf-fonts.config.dist.yml fonts/dompdf-fonts.config.yml

1. Copy source font into fonts/.
2. ./vendor/bin/import.php fonts/dompdf-fonts.config.yml

For example:

composer require aklump/dompdf-fonts
mkdir fonts
cp vendor/aklump/dompdf-fonts/dompdf-fonts.config.dist.yml fonts/dompdf-fonts.config.yml

1. Download one or more font families, say from https://fonts.google.com
2. For use with DomPDF you only need the .ttf versions. Copy those to your source directory. In the examples shown below, that directory is ./fonts.
3. You will need up to four versions of the font: normal, bold, italic and bold italic.

Example file tree.

.
├── dist
│   └── dompdf_fonts
│       ├── Merriweather--bold-italic.ttf
│       ├── Merriweather--bold-italic.ufm
│       ├── Merriweather--bold.ttf
│       ├── Merriweather--bold.ufm
│       ├── Merriweather--italic.ttf
│       ├── Merriweather--italic.ufm
│       ├── Merriweather--normal.ttf
│       ├── Merriweather--normal.ufm
│       ├── _style.scss
│       └── installed-fonts.json
└── fonts
    ├── dompdf-fonts.config.yml
    ├── Merriweather--bold-italic.ttf
    ├── Merriweather--bold.ttf
    ├── Merriweather--italic.ttf
    ├── Merriweather--normal.ttf
    └── dompdf
        └── import.php

1. dompdf-fonts.config.yml should have been copied from dompdf-fonts.config.dist.yml when you installed this, if not you must manually do so now.
2. Update dompdf-fonts.config.yml as appropriate. All paths are relative to dompdf-fonts.config.yml's parent directory.

File: _dompdf-fonts.config.yml

sources:
  - ../Merriweather*.ttf
output: ../../dist/dompdf_fonts/

1. Run php vendor/bin/import.php path/to/dompdf-fonts.config.yml to process your fonts.
2. Inspect to make sure your output directory contains the necessary files.

1. Set the fonts directory to match output.path on every new DOMPDF instance in your code. This is an example from a Drupal 9 module.

$options = new \Dompdf\Options();

// Determine the configuration directory by reading the import config.
$fonts_base_path = \Drupal::service('extension.list.module')
    ->getPath('my_module') . '/fonts';
$fonts_config = \Symfony\Component\Yaml\Yaml::parseFile($fonts_base_path . '/dompdf-fonts.config.yml');
$fonts_dir = realpath($fonts_base_path . '/' . $fonts_config['output']['path']);
$options->setFontDir($fonts_dir);

$dompdf = new \Dompdf\Dompdf($options);

1. To see your font in the browser you must import the SCSS partial. When only rendering PDFs, DOMPDF does not use _style.scss.

File: my_module/scss/_pdf.scss

@import "../dist/dompdf_fonts/style";

@mixin pdf_font_serif {
  font-family: Merriweather, Georgia, Times, "Times New Roman", serif;
}

h1 {
  @include pdf_font_serif;
}

• https://opentype.js.org/font-inspector.html
• https://fontforge.org/en-US/