NSUnderlineStyleAttributeName Underline spacing
I want the underline to be below the text like any other normal underlining mechanism. However, with NSAttributed string it leaves holes with "g's" and "y's"
example:
How it should look: 
How can I increase the spacing between the underline and label?
Answer
There is no way to control that behaviour with NSAttributedString or CoreText (apart from drawing the underline yourself). NSAttributedString has no option for that (and CoreText hasn't got one, either).
On Apple systems, the first version (with the gap) is the "expected" behaviour as it's the one Apple provides and is used throughout the system (and apps like Safari, TextEdit, etc.).
If you really, really want to have underlines without a gap, you need to draw the string without an underline and draw the line yourself (which I needed to do in one of my projects and I can tell you it's hard; see this file, search for "underline").