I have a brother printer and am trying to print a pre-printed envelope that is an adobe file. When I do, the entire front of the envelope is covered with black ink (grayed out)-- so that you can't see any writing. Any idea why it is doing this? Or how to fix it? I am using a mac if that makes a difference. The more I think about it, I think it's an adobe issue, but I don't have any ideas how to fix it.