Underlining in Illustrator is broken by default. But that is actually a gift.

It draws a line exactly at the baseline of the font at the exact weight of the font’s stem. Why it fails: It doesn't scale well. It ignores ascenders and descenders. If you have a lowercase 'g' or 'y', the line will slice right through the tail.

Underlining isn't boring. In Illustrator, it is a chance to show that you understand typographic space, vector math, and nesting effects. Don't waste it on a default setting.

Here is how to master the three distinct philosophies of underlining in Illustrator, and why you should probably never use the default "Underline" option again. Yes, it exists. Open your Character panel (Window > Type > Character) and click the "Underline" icon (the T with a line under it).

In the world of vector design, an underline isn't a text decoration; it is a graphic element. Treating it as such is the difference between looking like a legal clerk and looking like a professional typographer.

Use the for global underlines. Use Line Segments for artistic, variable underlines. Only use Outlines if you are physically warping the underline to wrap around a 3D object.

If you’re migrating from Microsoft Word or Google Docs, Adobe Illustrator feels like a betrayal. You highlight your text, you look for that magic U button... and it isn’t there. Or, if you find it, it looks like a razor-thin wire sitting two miles away from your words.