how to add the border for only roman numbered pages?

Question

to all

Previously asked the question how to add the borders for selected pages,i got the answer but i'm facing problem.I'm using two types of page numbering roman and Arabic.\AddToShipoutPictureBG{\ifnum\value{page}<3 this line will select the pages.The boarders will come both roman and Arabic pages. but i want only in the roman page numbered page only not in the Arabic page numbered pages. so plz help me what changes i have to make...

Thank you

\documentclass[12pt]{book}
\usepackage{tikz}
\usepackage{eso-pic}
\usetikzlibrary{calc}
\usetikzlibrary{decorations.pathmorphing}
\AddToShipoutPictureBG{\ifnum\value{page}<3
\begin{tikzpicture}[overlay,remember picture]
\draw [line width=3pt]
       ($ (current page.north west) + (1.5cm,-2.0cm) $)
    rectangle
    ($ (current page.south east) + (-1.5cm,1.8cm) $);
\draw [line width=1pt]
    ($ (current page.north west) + (1.65cm,-2.15cm) $)
    rectangle
    ($ (current page.south east) + (-1.65cm,1.95cm) $); 
\end{tikzpicture}%
\fi}
\begin{document}

\pagenumbering{roman}
\begin{titlepage}


\section*{\large{DECLARATION}}

%-----some paragraph-------

\newpage

\begin{center}
\section*{\large{ACKNOWLEDGEMENT}}
\end{center}

%-----some paragraph-------
\end{titlepage}
\newpage

\tableofcontents
\newpage 

\pagenumbering{arabic}

%-----Start chapters-------
\end{document}

Answer 1

Use \frontmatter and \mainmatter:

\documentclass[12pt]{book}
\usepackage{tikz}
\usepackage{eso-pic}
\usetikzlibrary{calc}
\usetikzlibrary{decorations.pathmorphing}
\makeatletter
\AddToShipoutPictureBG{\if@mainmatter\else
\begin{tikzpicture}[overlay,remember picture]
\draw [line width=3pt]
       ($ (current page.north west) + (1.5cm,-2.0cm) $)
    rectangle
    ($ (current page.south east) + (-1.5cm,1.8cm) $);
\draw [line width=1pt]
    ($ (current page.north west) + (1.65cm,-2.15cm) $)
    rectangle
    ($ (current page.south east) + (-1.65cm,1.95cm) $); 
\end{tikzpicture}%
\fi}
\makeatother
\begin{document}
\frontmatter
\begin{titlepage}
\section*{\large{DECLARATION}}

%-----some paragraph-------

\newpage

\begin{center}
\section*{\large{ACKNOWLEDGEMENT}}
\end{center}

%-----some paragraph-------
\end{titlepage}

\tableofcontents

\mainmatter
%-----Start chapters-------
\chapter{foo}

\end{document}

Answer 2

From your question is not clear, if you like to have frame around all roman numbered pages or just around first two roman numbered package. In later case the simplest way is to define new command for drawing frame and insert this command at this two pages:

\documentclass[12pt]{book}
\usepackage{tikz}
\usetikzlibrary{calc}
\newcommand\frm{
\begin{tikzpicture}[overlay,remember picture]
\draw [line width=3pt]
    ($ (current page.north west) + (1.5cm,-2.0cm) $)
    rectangle
    ($ (current page.south east) + (-1.5cm,1.8cm) $);
\draw [line width=1pt]
    ($ (current page.north west) + (1.65cm,-2.15cm) $)
    rectangle
    ($ (current page.south east) + (-1.65cm,1.95cm) $);
\end{tikzpicture}%
}
\usepackage{lipsum}

\begin{document}
\frontmatter
\begin{titlepage}
\thispagestyle{empty}
\frm
\section*{\large{DECLARATION}}

\lipsum[1]

\clearpage
\thispagestyle{empty}
\frm

\begin{center}
\section*{\large{ACKNOWLEDGEMENT}}
\end{center}

\lipsum[2]
\end{titlepage}

\clearpage

\tableofcontents

\clearpage
\mainmatter
\chapter{Introduction}

\chapter{State of the art}

\end{document}