For Variable Font, I’m not sure how the implementation differs between slant and italic. For Variable Font, I assume slant is implemented like other axes in that there are variable values of slant that change the slant, like variable values of weight will change the weight. For Variable Font italic, is there a way to substitute a different glyph with some different appearance as might be the case for a true italic as opposed to oblique. If the italic is a substituted glyph with the slant already applied, how does this get into a Variable font without having a master axes associated with it. If there is a master axis that is used to modify the slant of a substituted glyph, will that work. Some explanation of how to get a variable font italic axis to work would help me. Thanks.
ital axis effectively replaces the Italic bit (of Style Linking) for Variable Fonts. You can have it with concrete values 0 and 1, or even fluent, if you like.
And it doesn’t need to be in a single file.