I'm not trying to draw a 9 part image.
I always have a hard time constructing images that look good in a texture rounded button, similiar to the buttons you see in NSToolbar in Finder, or Safari or whatever.
The height of a texture rounded button is 25 points but NSButton seems to inset the image a bit in this mode. Not sure if I missed the API to determine that inset amount. Built in template images work for the most part but there aren't that many of them. It seems that some of the templates may have a have a little transparent margin that makes them scale nicer inside the texture rounded button. I can't get the button to look the way I want in IB when playing with image alignment and the scale mode. I end up just subclassing NSButtonCell to fix it.
Not sure if I'm making my image the *wrong way* for this. Making an all black PNG and setting it as a template image comes out of Interface Builder fuzzy. Not sure if the lines are too thick on these PNGs. They look nice on iOS though. I am on a non-retina Mac though.