Italic Angles

Glyphs
1

I see some typefaces with negative italic angles in their value and it got me confused as to why is that. Could you guys explain that a bit further?
Thanks!
Rodrigo

2

I am not sure I understand what you mean. Can you give an example? Which typeface?

3

I guess it might be a bug whenever I open an italic .otf font say from the system.

This is the system’s caslon
http://cl.ly/image/2q3d2O0P0i46
http://cl.ly/image/1m321C1B1u0Y

In my mind the angle should follow the italic slope… right?

4

Which Caslon are you referring to? OS X’s BigCaslon.ttf does not have an italic. And I couldn’t reproduce this with any of Adobe’s italic Caslons I have installed.

I’m surprised that it reads something besides zero. When importing a font, I believe Glyphs ignores the italic angle set in the font’s CFF and/or post table and always leaves it at zero.

5

There was a but in the italic angle import. I fixed it.

6

According to the specs, it seems that the italic angle should be negative.

https://www.microsoft.com/typography/otspec/post.htm

http://typedrawers.com/discussion/comment/4768

7

Glyphs uses a more intuitive clockwise angle measurement but should set all angles in the exported font file according to the OT specs. Does it not do so?