# How can I make a path with arrow “open” or “two-sided”?

I've drawn this arrow:

But want it to look like this:

How can I do that? This is my code for the first arrow:

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows.meta}
\begin{document}
\begin{tikzpicture}
\node (n1) at (0,0) {n1};
\node (n2) at (4,0) {n2};
\draw[-{Latex[length=1.2cm,open]}, blue, line width=0.1cm] (n1.east) to (n2.west);
\end{tikzpicture}
\end{document}


You could try something fairly simple like this:

\documentclass[border=10pt,tikz]{standalone}
\usetikzlibrary{arrows.meta,calc}
\begin{document}
\begin{tikzpicture}
\node (n1) at (0,0) {n1};
\node (n2) at (4,0) {n2};
\draw [double distance=2.5mm, -{Latex[length=1.2cm,open]}, blue, line width=1mm] (n1.east) to (n2.west);
\draw [double distance=.5mm, white, line width=1mm] (n1.east) to ($(n2.west) - (11mm,0)$);
\end{tikzpicture}
\end{document}


If you need to draw several, using the pic syntax might be the way to go:

\documentclass[border=10pt,tikz]{standalone}
\usetikzlibrary{arrows.meta,calc}
\begin{document}
\begin{tikzpicture}
[
pics/my arrow/.style n args=2{
code={
\draw [double distance=2.5mm, -{Latex[length=12mm,open]}, line width=1mm, pic actions] (#1) to (#2);
\draw [double distance=.5mm, white, line width=1mm] (#1) to ($(#2) - (11mm,0)$);
},
},
]
\node (n3) at (0,-1) {n3};
\node (n4) at (4,-1) {n4};
\pic [red] {my arrow={n3}{n4}};
\end{tikzpicture}
\end{document}


cfr's solution can be adapted to be a regular style with postaction. Also a shorten > option can be used to avoid calc tikzlibrary.

\documentclass[border=10pt,tikz]{standalone}
\usetikzlibrary{arrows.meta}
\begin{document}
\begin{tikzpicture}
[
my double arrow/.style={double distance=2.5mm, -{Latex[length=12mm,open]}, line width=1mm,green,
postaction={draw,double distance=.5mm,line width=1mm, white,-, shorten >=10mm}},
]

\draw[my double arrow] (0,1) to (4,1);

\draw[my double arrow, red] (0,0) to (4,0);

\end{tikzpicture}
\end{document}


• This looks great, but it draws a white rect inside the shaft of the arrow. Can the middle of the shaft be transparent? – Johan - reinstate Monica Jul 26 '17 at 14:31
• @Johan I think that could be asked as a question; many people will be interested. – Cyriac Antony Jun 27 at 11:32