Blurry images when using sign and fill, Only Acrobat DC has this issue

[SRFORTUNE9]

I have an issue with one of my supported designers, he is using Acrobat pro DC to sign large formatted documents.  Other users with acrobat XI & X pro don't have any issues with resolution this happens with all PDF's he opens but the larger the worse it is typical size is 120x36in.  I should add that if he is just viewing the document it's fine it only blurs when print and sign tool opens. 

any ideas besides downgrading him to XI