Saving file with white background instead of transparent

[Stargirlgemini]

I am on illustrator, trying to save a project as a PDF but every time I save it the background is transparent, and I need it to be white. I made the pages as artboards and I'm not sure if that is related to the issue. 

[sishamIAGD]

Hi there, if you want a white background you need to add one. So, select the rectangle tool and have white fill then cover the artboard and send it to back.

[Ton Frederiks]

I f you view the file in Acrobat, make sure that Preferences > Page Display > Show transparency grid is turned off.