Latex rounded corner in entire page
\documentclass[12pt]{scrartcl}
\usepackage{lipsum}
\usepackage[a4paper,margin=1in,heightrounded]{geometry}
%
\usepackage{tikz}
%
\usetikzlibrary{calc}
%
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[overlay,remember picture]
\draw [line width=1pt,rounded corners=7pt,
]
($ (current page.north west) + (1cm,-1cm) $)
rectangle
($ (current page.south east) + (-1cm,1cm) $);
\draw [xshift=4mm,dashed,line width=1pt,rounded corners=7pt]
($ (current page.north west) + (.5cm,-.5cm) $)
rectangle
($ (current page.south east) + (-.5cm,.5cm) $);
\draw [line width=1pt,rounded corners=7pt]
($ (current page.north west) + (1.5cm,-1.5cm) $)
rectangle
($ (current page.south east) + (-1.5cm,1.5cm) $);
\end{tikzpicture}
%
\lipsum[1-6]
\end{document}