My PDF files are printing with unwanted shadows in the text. This does not happen with page or word documents. How do I fix?

[suzanned43992636]

My PDF files are printing with unwanted shadows in the text. This does not happen with page or word documents. How do I fix?

[ERIC278182483fzn]

I have the same problem that occurs only with pdf documents. Any other document is perfectly printed which seems to mean that the printer is ok, bearing in mind that I have tried different printers. I am using Acrobat Pro and MacBook Air. Grateful for any help.

Eric