| |
| | | The Em | Typophile |
 | | All “That” uses the term “em” in the context of a given size during composition, and there it means “whatever the point size is times X”, so yes, “an em” is a sliding measure, but it is so because of the shorthanded nature of the command, and… it is not The Em. |
 | | In metal foundry type the EM is the body size (height) of a piece of type in a font, and is also normally approximately equal to the width of a cap M. In digital type the EM is the square grid upon which glyphs are drawn and encoded. |
 | | The em is not equal to each em-dash, but in approximation, or in many cases, it is. Similarly, the mechanical horsepower as a measurement unit does not equal the operating power of every horse in the world, but it is an approximation. |
| typophile.com /node/27742 (5716 words) |
|