Fake Italics angle

hrant's picture

So is there a way to decide the angle that software (like Word or Explorer) uses when slanting a font that doesn't have an italic? There seems to be a field for it in one of FontLab's "Font Info" panels, but it doesn't effect the results.


John Hudson's picture

The FontInfo field to which you refer is probably the Slant Angle. This does something other than what you want: it is a way to mechanically oblique a Type 1 on output, and was used a means to ship 'italic' fonts for families that don't have true italics. The original Adobe/Linotype Helvetica italic PS fonts used this mechanism, for example. The italic fonts were obliqued in use, but if you opened them in FontLab you would find that the outlines were upright -- identical to the roman fonts in fact -- and the obliques you saw in apps were as a result of the Slant Angle setting.

I'm not aware of any setting to do what you want, but have a look at the OS/2 table spec. That would be the obvious place for such a setting in TT and OT fonts.

hrant's picture


> the OS/2 table spec

Is this something accessible from FontLab, or a hand-coding deal?


twardoch's picture


OpenType PS (.otf) fonts also use the Slant operator so "dynamic" slanting is possible. In fact, for oblique typefaces, there are advantages of using the Slant operator instead of manually slanting outlines. You can hint the upright font for PostScript once, and then let ATM interpret the hinting and do the slanting. Authinting of upright fonts usually works better than autohinting manually slanted fonts.


seems like neither the OpenType spec nor the FOND Mac resource allows to specify the angle of automatic slanting if the italic/oblique style is missing.


John Hudson's picture

Thanks for the extra details, Adam. I'm not surprised that support for the Slant operator has been carried over from Type 1 to CSS. I have to admit, that I've just about given up on PS fonts: Ross has made some CFF OT fonts, but I've done nothing but TrueType for the past couple of years.

Hrant, most aspects of the OS/2 table can be input via FontLab, e.g. the TT/OT vertical metrics, codepage and Unicode range bits, etc., but most of these are not identified specifically as OS/2 table entries in the FontLab interface: you have to be familiar with the spec to know which FontLab fields correspond to which sfnt table entries.

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