TikZ picture on the entire frame in beamer without using overlays

Question

I have a beamer presentation with several TikZ diagrams that spread across the entire frame, i.e., use the full screen size. I am using the overlay option to make sure the picture captures the entire frame:

\begin{tikzpicture}[overlay, remember picture]
  ...
\end{tikzpicture}

The problem is that these diagrams are messed up on the notes pages, that can't align them properly.

Is there a way to make a TikZ picture spread across the full page? I tried using a node that is as large as the entire frame, but it was displayed with some margin between it and the top and left edges of the frame.

Edit

When not using an overlay or background template, the result is shifted to the right:

\begin{frame}
  \begin{tikzpicture}
    \node[minimum width=\paperwidth, minimum height=\paperheight, anchor=north west] (a) {};
    \draw [very thick] (a.north west) -- (a.south east);
    \draw [very thick] (a.north east) -- (a.south west);
  \end{tikzpicture}
\end{frame}

Answer 1

If you wrap your tikzpicture in \makebox[\textwidth][c]{...}, the picture will be properly centered and stretch across the whole width.

\documentclass{beamer}
\usepackage{tikz}

\begin{document}

\begin{frame}
 \makebox[\textwidth][c]{\begin{tikzpicture}
    \node[minimum width=\paperwidth, minimum height=\paperheight, anchor=north west] (a) {};
    \draw [very thick] (a.north west) -- (a.south east);
    \draw [very thick] (a.north east) -- (a.south west);
  \end{tikzpicture}
  }
\end{frame}

\end{document}

Answer 2

Here you have two options, second is what Jake suggested and first was taken from How to insert a background image in a beamer frame?

\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usepackage{graphicx}

\begin{document}

{
\usebackgroundtemplate{%
\begin{tikzpicture}
\node[draw,very thick,minimum width=\paperwidth-\pgflinewidth,minimum height=\paperheight-\pgflinewidth] [anchor=north west] (mynode) {My node};
\draw (mynode.north west)--(mynode.south east);
\draw (mynode.south west)--(mynode.north east);
\end{tikzpicture}
}
\begin{frame}{Frame with background}
\begin{itemize}
\item 1
\item 2
\item 3
\end{itemize}
\end{frame}
}

\begin{frame}{Frame with overlay picture}
\begin{tikzpicture}[overlay, remember picture]
\node[draw,very thick,minimum width=\paperwidth-\pgflinewidth,minimum height=\paperheight-\pgflinewidth] at (current page.north west) [anchor=north west] (mynode) {My node};
\draw (mynode.north west)--(mynode.south east);
\draw (mynode.south west)--(mynode.north east);
\end{tikzpicture}
\begin{itemize}
\item 1
\item 2
\item 3
\end{itemize}
\end{frame}
\end{document}

EDIT

From beamer user guide 8.2 Frame and Margin Sizes

Aside from using these options, you should refrain from changing the “paper size.” However, you can change the size of the left and right margins, which default to 1cm. To change them, you should use the following command: \setbeamersize{⟨options⟩}

The following ⟨options⟩ can be given:

• text margin left=⟨TEX dimension⟩ sets a new left margin. This excludes the left sidebar. Thus, it is the distance between the right edge of the left sidebar and the left edge of the text.

The problem is that this command is only valid in the preamble, so it changes all presentation margins. Here you have a new example:

\documentclass{beamer}
\usepackage{tikz}
\setbeamersize{text margin left=0pt}
\begin{document}
\begin{frame}
  \begin{tikzpicture}
    \node[minimum width=\paperwidth, minimum height=\paperheight, anchor=north west] (a) {};
    \draw [very thick] (a.north west) -- (a.south east);
    \draw [very thick] (a.north east) -- (a.south west);
  \end{tikzpicture}
\end{frame}
\end{document}

and its result

Answer 3

Here's my preferred solution: one which uses a method for absolute positioning described here and here. It aligns the "X" perfectly.

\documentclass{beamer}
\usepackage{tikz}
\begin{document}
    \setbeamertemplate{navigation symbols}{} %remove navigation symbols
    \begin{frame}
        \begin{tikzpicture}[overlay, remember picture, shift={(current page.south west)}]
        \draw (0,0) -- (\paperwidth, \paperheight);
        \draw (0,\paperheight) -- (\paperwidth, 0);
        \end{tikzpicture}
    \end{frame}
\end{document}