To use Tumblr’s new fonts, create a text post.
1) Click the gear icon.
2) Change the Text editor to HTML.
3) Use HTML paragraph tags around your text as follows. (The Preview won’t show the fonts at this time.)
Fancy
Typewritery
Quotey
4) Publish (or save draft) to see the fonts on your post via the Dashboard. (The Tumblr Official theme also shows the fonts on text posts.)REDACT THAT LAST POST I JUST MADE THE ANSWER IS HERE