Mathematical Double-Struck Small B 𝕓

Visual Description: The character appears as a small b with a double-stroke, giving it a chalkboard look. It feels compact and serifless, with extra line work that suggests emphasis. In many fonts it retains the familiar rounded belly and a second leg that hints at depth. This glyph stands out in formulas & comparisons.

Meaning & Usage: The double-struck small b is used to mark a special object in a formula. It signals a distinguished object, or a value tied to a convention. Readers scan for its visual cue quickly, just as they do for bold symbols in notes. Software and calculators may render it to stand apart as a named constant or a designated class.

Historical Background: The double-struck style grew from the need to mark important mathematical objects on boards and pages. It emerged as a visual convention, not a single invention. Over time, educators and writers adopted it to separate standard text from special notation, preserving clarity without changing the underlying meaning. The practice remains general and portable across disciplines.

Practical Use: In textbooks and software, the double- struck small b appears to name a class of objects or a constant in a clean, recognizable way. UI tools may offer a font style toggle or a quick button to switch to a blackboard-like look for comparisons or derivations. It helps focus attention during complex steps.

See our category page for related symbols.

Look‑alikes: b (U+62).

Need styled alternatives? Try the Fancy Text tool.