# TikZ: ordinary arrow tip on double line

I like the ordinary arrow tip that you get in TikZ from \draw [->] (a) to (b);. In my document I have lots of ordinary lines like this, and also lots of doubled lines like \draw [double,->] (c) to (d);. But it looks a bit strange, since the arrow tips are different. I think it would look better if all the lines used the ordinary arrow tip.

So, here's my question: how can I get an arrow tip myarrow such that \draw [double distance=0.5pt,-myarrow] (c) to (d); gives me exactly the same arrow tip as with an ordinary line? I would like this to work for a range of values of double distance, say less than 1pt.

Here's one solution:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows.meta}
\tikzset{%%
>={To[length=6pt]}
}
\pagestyle{empty}
\begin{document}

\begin{tikzpicture}
\draw[->] (0,0) -- (1,0);
\draw[double,->] (0,1) -- (1,1);
\end{tikzpicture}

\end{document}


This will force the arrows to have the same length, but this will also prevent them from scaling appropriately if you change the width of the line (but perhaps that's not an issue for you).

• This is a nice approach. The only problem I see is that the double line protrudes in front of the arrow head slightly. Can this be fixed? – Jamie Vicary Dec 20 '14 at 17:25
• @AEllett: looking at the awesome power of the new PGF3 arrow library it seems this must be possible, but I can't work it out from a quarter of an hour reading the manual. – Jamie Vicary Dec 20 '14 at 18:05