@KRADL1 is the method we use. I originally got it from @Lake I have been intending to do some screen captures and a tutorial on how to do it and post it here. Just not enough time.
You can set the label to auto rotate and resize, it will save time since the UPS labels need to be shrunk a little and the Amazon barcode needs to be printed at 100%
To solve the problem you are having now, be sure your Zebra is not set to grayscale. That will cause the dithering.
Being Yankee Frugal, I am not going to pay a third party for something I can figure out on my own, with the help from an Ace.