You can also further stylize your custom fonts using CSS code and take your website to the next level. To add fonts to Squarespace & change fonts, follow these steps: Upload your custom font; ...

How to Change Body Text Font on Tumblr. ... In order to use a non-standard Web font you must attach its CSS style sheet in your theme's header (see Tips).

Fortunately, Tumblr enables you to change the font size for your blog's text by giving you direct access to the raw CSS or Cascading Style Sheet code of your theme. Log in to your Tumblr blog.