Grab attention on the Twitter timeline with bold headers and stylish tweet text.
The X timeline sets posts at a small size in a light sans-serif, tightly stacked. That favours a specific set of styles. Sans-serif bold is the obvious one for a hook line. Fullwidth ｔｅｘｔ reads clearly because the spacing does the work. Small caps read as a deliberate quiet header. Monospace stands out as a code-like aside. Script and blackletter, which look good on a profile page at larger size, turn to noise at timeline size and are better kept to the display name. The interleaved styles, a symbol between every letter, read as decoration for a single word, not a sentence.
The common pattern is a styled first line on the opening post of a thread, the part that shows in the timeline before someone expands it, and plain text after. Quoted posts render styled text the same way. Two places to avoid it: hashtags, which do not link when styled, and image alt text, which is read aloud and where mathematical characters are read as their long names. Character counting is straightforward: one styled letter is one character, so a bold headline costs the same as a plain one. X: bio 160 characters, display name 50, @handle 15 ASCII characters.
Sans-serif bold for a hook, fullwidth for spacing, small caps for a quiet header. Script and blackletter are too fine at timeline size.
No. #𝘵𝘦𝘹𝘵 is a different string to X than #text and will not link. Keep hashtags plain.
It changes how search sees it: a styled keyword is not matched by a plain search. There is no documented penalty for using it, but keep any word you want to be found in plain text.