Let's assume that the blue rectangle in the next image 1 represents the page borders, the gray rectangle represents page margins and, the black one represents what I need to draw using Tikz.

I need it there as a background of my text, but the tikz image align as a text on margins.
\tikz[remember picture,overlay] {\draw[line width=2mm,blue] (current page.south west) rectangle (current page.north east);}If you are going to use this for all pages you can use thebackgroundpackage. – azetina Aug 24 '14 at 15:03