It seems that, when using Tikz, nodes and/or the tikzpicture environment add space around a drawing. An example is shown in the following MWE, where a simple square is drawn three times. First it is drawn in just a single tikzpicture, then in a nested tikzpicture, and finally in a nested tikzpicture with the inner sep adjusted. This last image makes me suspect there are some widths that need to be set to zero.
\documentclass[tikz]{standalone}
\standaloneenv{tikzpicture} % New page for every image
% The code for the square
\newcommand\Square[1][]{
\begin{tikzpicture}[#1]
\draw (0,0)--(1,0)--(1,1)--(0,1)--cycle;
\end{tikzpicture}
}
\begin{document}
% Image with correct cropping
\Square[x=1.5cm,y=1.5cm]
% Image with a lot of space
\begin{tikzpicture}
\node at (0,0){
\Square[x=1.5cm,y=1.5cm]
};
\end{tikzpicture}
% Image with some cropping
\begin{tikzpicture}
\node[inner sep=0pt] at (0,0){
\Square[x=1.5cm,y=1.5cm]
};
\end{tikzpicture}
\end{document}
The three output images (or pages) are the following.

How does one eliminate this spacing? Nesting these environments is necessary for the specific problem I'm working on, and \includegraphics[clip]{} doesn't work in combination with \standaloneenv{tikzpicture} (which was tried just in case the standalone failed at cropping).

nodeandtikzpictureetc, and then it turns out to be a white space. Thanks! – Betohaku Apr 28 '13 at 15:35