Firefox's update to v 34.0.5 has resulted in labels printing blank. If you are using Firefox as your browser on a Mac, you should be able to correct this problem by following these steps.
First check for the version by going to the top left corner to Firefox > About and check the version.
If your's says 34.0.5, please visit Mozilla support for a step by step guide to ensure that your PDFs:
If neither of these solutions fixes the problem, please double check that Adobe Reader is working properly. Learn more here.