fun fact: you can use mm/cm or freedom units in CSS [1]. YMMV outside of printing though, at least on low-DPI devices the rendering results might not make too much sense. If you're really adventurous, CSS offers even more dedicated printing functions such as pagination [2].

[1] https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/V...

[2] https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Frag...