Arabic vertical metrics

Hi there,

As you can see in the image below i have encountered a vertical metrics issue that i can not understand.
I don’t know why but if i use latin script the typeface is perfectly centered in the box, but switching to arabic script it appears with an extra padding below the line. I have follow the vertical metrics tutorial nonetheless the problem still remains. What am I missing?

systems have different behavior when dealing with vertical metrics.

in your case it might be due to some diacritic or anchors


(-)hheaDesender = (+)winDesent = (-)TypoDesender
hheaAscender = winAscent = TypoAscender
all diacritic points/anchor points should be in between
with same gap between highest point to the ascenders
and between the lowest point to the descenders

The Vertical Metrics tutorial describes how web browsers determine top and bottom padding in div’s. I recommend to follow the ‘Webfont Strategy’.

The CSS needs to be good too of course. The best font cannot fix the web design.

In short:

  1. Sync typo and hhea values.
  2. Make sure your letters look good between your typo/hheaAscender and typo/hheaDescender. Verify with the Show Vertical Metrics plug-in (get it for free from Window > Plugin Manager).
  3. Insert the Use Typo Metrics parameter.