Use Hair and Thin Spaces for Fine Adjustments
When a full word space is too wide but no space is too tight, use hair spaces ( ) or thin spaces ( ): around em dashes, after citations, between nested punctuation, and around special characters.
Incorrect (no space or full space around em dashes):
<p>Typography—the art of type—matters.</p> <!-- too tight -->
<p>Typography — the art of type — matters.</p> <!-- too loose -->Correct (thin spaces around em dashes):
<p>Typography — the art of type — matters.</p>Common uses:
| Context | Spacing |
|---|---|
| Around em dashes |   or   |
| Between quote and attribution |   |
| Around midpoint separators |   |
| Between units and values |   (e.g., 5 kg) |
Use   (U+200A, thinnest) when   (U+2009) still feels too wide.