User Guide

Glyph Window
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Vertical Alignment Options
When you select 100% as the zoom value, FontLab needs to choose a
scaling factor to fit the font unit space in the Glyph Window. Two vertical
levels in the font space define this scaling: Visual Ascender and Visual
Descender:
Visual Ascender
Visual Descender
Editing Field
When you select 100% zoom, it means that Visual Ascender is fitted to the
top of the editing field and Visual Descender to the bottom.
The same values are used to build the icons that you see in the Font
Window or panels like Collection/Classes.
To set Visual metrics, use the Glyph page of the Options dialog box
(Tools > Options menu):
Values are measured in percentage of font UPM, so –20% is –200 if UPM is
1000 and –410 if UPM is 2048.