I have created pdfs from modified TIFs...pdf looks great but pages print wrong (some pages print too big for page)

I have scanned material to a TIF, cleaned it up (reoriented and removed stray marks and edges) in Windows Paint, resaved as TIF, assembled into pdf, but when I go to print the document (which looks great as I flip through its electronic pages), some of the pages exceed the size of the printed page.