If I take a screenshot on my MacBook Pro, I get a rather large PNG.
When I drag and drop it into Omnigraffle, the program is smart enough (somehow) to know that I’m working with a screenshot from a high, retina resolution monitor. Other Mac applications have gotten pretty good at this too–maybe they pay attention to the PNG’s “144 pixels/inch” DPI.
Anyway–I do my mark ups of the image, I export a 72 dpi image, and I’m good to go… except that the image looks blurry. It looks blurry on both my MacBook’s display AND on a non-retina display.
HOWEVER, if I plug a non-retina monitor into my MacBook, and put the application on THAT screen, and take my screenshots, drop them into Omnigraffle, and do my markups, everything works much better. Sharp lines, image looks good everywhere.
I’d like to be able to take screenshots and work wherever I am, without an external monitor. Those screenshots must present the UI I’m doing a screenshot of sharply, whether the reader is using a retina display (or other ultra-high resolution tech, I think Retina is an Apple name?) or a more standard monitor.