How can a bold arrow be bent correctly?
I use the following code, but it looks horrible:
\tikzset{%
thick arrow/.style={
-{Triangle[angle=90:1pt 1]},
line width=1.0cm,
draw=gray
}
}
\tikzstyle{software} = [draw, text width=10em, minimum height=6em, text centered, line width=1pt, color=mydarkblue, fill=mylightgray, text=mydarkblue, font=\normalsize\bf\sffamily]
\centering
\begin{tikzpicture}[node distance = 6em]
\node[software](softA) {Software A};
\node[software](softB)[left = of softA] {Software B};
\draw [thick arrow] ($(softB.north)+(1,1em)$) [bend left=45] to ($(softA.north)+(-1,1em)$);
\path [decorate,decoration={text along path,
text={|\footnotesize\bfseries\sffamily\color{white}|DATA A},text align=center}] ($(softB.north)+(1,1.5em)$) [bend left] to ($(softA.north)+(-1,1.5em)$);
\draw [thick arrow] ($(softA.south)-(1,1em)$) [bend left=45] to ($(softB.south)+(1,-1em)$);
\path [decorate,decoration={text along path, text={|\footnotesize\bfseries\sffamily\color{white}|DATA B},text align=center}] ($(softB.south)+(1,-1.5em)$) [bend right=45] to ($(softA.south)+(-1,-1.5em)$);
\end{tikzpicture}
Here is what the code creates: the arrows are very strangely bent and don't look curved properly and uniformly.


\usetikzlibrary{bending}help? (Incidentally, it is always best if you add a\documentclass(articleis usually fine), and a minimal preamble with the necessary packages, TikZ libraries and color definitions. It can be a bit tedious to work that out for ourselves sometimes. Ideally we should be able to copy-paste your code into our editor, and compile without having to do any modifications.) – Torbjørn T. Jan 11 '17 at 16:31-Triangle[bend, ...]together with @TorbjørnT. may give even better results. That is, mostly it does, but occasionally it doesn't. – cfr Jan 11 '17 at 23:46