Generate heavy, high-impact bold typography that dominates any digital timeline.
Weight in unicode text comes from four alphabets. Mathematical sans-serif bold 𝗙𝗔𝗧 is the cleanest heavy. The same shapes as a system font at bold weight, so it reads as emphasis. Mathematical bold serif 𝐅𝐀𝐓 has thick verticals and serifs and reads as editorial or vintage. Bold fraktur 𝕱𝕬𝕿 is the heaviest by ink coverage, dense blackletter with almost no white inside the letters. The filled squares 🅵🅰🆃 are not strictly a weight but read as the heaviest of all, because each letter is a solid block. Fullwidth ＦＡＴ is not heavy but reads as wide, which is often what a fat-text search wants.
Heaviness and legibility trade off as size drops. Sans-serif bold loses nothing at any size. Bold serif holds up to bio size. Bold fraktur starts to close up, the counters fill in, at around 12 pixels, which is smaller than most bios but larger than a kill feed. Filled squares become a solid bar at small sizes; they are a headline style, not a body style. If the fat text is for a banner, a story headline or the first line of a post, any of the four works. If it is for a display name that will be shown small, sans-serif bold is the one that stays fat and readable.
By ink on the page, bold fraktur, then the filled squares. For a clean heavy that stays legible small, sans-serif bold.
Sans-serif bold and bold serif do. Bold fraktur and the filled squares do not, so digits pass through plain in those styles.
Not in weight. Unicode has no black or heavy weight beyond bold. For more visual mass, use bold fraktur or the filled-square alphabet.