bitbank:
"Formatted Text" doesn't describe well enough what you want to do. Please provide examples.
For examples like text presented by an e-book reader. Or HTML formatted text pages by a browser. Or markup text like *.MD in GitHub. Or ODF in MS Word.
Just as easy as possible. Or in widespread use but not too complicated. And less memory hungry than bitmaps.
But maybe the method "any format" -> pdf -> jpeg" on host, to "jpeg -> jpeg renderer -> screen" on Arduino is better suited.