FontCreator Tutorials

Glyph Spacing and Optical Metrics

written by Erwin Denissen, published March 24, 2020

While designing your font you can add characters and glyphs without worrying too much about the metrics of each glyph, but before you consider adding kerning to your font, you must ensure the spacing between glyphs is optimal.

A font editor usually has several ways to adjust the side-bearings of each glyph, but FontCreator professional edition allows you to generate those metrics for your Latin characters with optical precision. Just open the Automatic Metrics wizard and use the optical Metrics option to generate the best optical space before and after each character. You might need to try different Glyph spacing factors, which allow you to provide a global distance factor. A large factor will result in more spacing between glyphs.

We’ve taken a couple of popular fonts, so you can see the power of this feature. Below you see the original font (first line) along with the font after running Optical Metrics (second line). Both with font size 14, and kerning is not applied as that would override spacing.

Sans Serif Fonts:

Serif Fonts:

With serif fonts you see optical metrics finds it hard to calculate good values for glyphs with bowls, e.g. the combination “be”, “pe”, and “po”. We might need to investigate that to further improve the algorithm.

Optical metrics took less than a minute per font. Not bad if you realize glyph spacing is considered as important as the design of the glyph outlines. Font designers can do without optical metrics, but they usually spent days or even weeks trying to find a good balance.

Perfect spacing between glyphs make a font stand out, and it avoids unnecessary kerning pairs.

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