Add outline to text in Preview Preview use to support adding an outline to text. 

Using a black outline with white fill for lettering was really nice for making words visible on dynamic backgrounds. Has this feature been removed in Version 8? Or is there another way to do this?
Unfortunately, I was unable to find a way to exactly imitate the desired behavior. You may have to simply create the outlined text in a different application and import it into Preview.

However, while it might not be exactly what you're looking for, you can create text with a background color. To do so, bring up the markup toolbar and create a new text box. Then, using the dropdown menu indicated in the below screenshot, select a background color.




The font, along with its color and size, can be modified by selecting the "A" icon to the right of the aforementioned menu. If you want a literal outline around the entire text box, that can be accomplished by selecting the dropdown to the left of the previously mentioned background color menu.