How can I improve the look of an arrowhead at the end of a small-radius arc?

Question

Arrow heads added to arches with small radius look ugly, they do not look symmetrical. Here is an example :

    \documentclass{article}
    \usepackage{tikz}
    \usetikzlibrary{arrows.meta}

    \begin{document}
    \begin{tikzpicture}[>=stealth]
    \draw[->] (0,0) arc (00:290:.15cm);
    \end{tikzpicture}
    \end{document}

This gives an arrow like (screenshot of 24x magnification):

enter image description here

What I would like to have is something like:

enter image description here

Is it possible, how?

Take a look at Create curved TikZ single arrow for one way of doing this. — Jake, May 12 '14 at 17:38
With TikZ 3.0.0 you might want to have a look to flexing and bending libraries (untested). — Claudio Fiandrino, May 12 '14 at 17:40
@ClaudioFiandrino it's enough to load bending. Could you turn your comment into an answer? — Gonzalo Medina, May 12 '14 at 17:54
@GonzaloMedina: sure, I will do it tomorrow: this laptop is TikZ 3.0.0 free ;) — Claudio Fiandrino, May 12 '14 at 18:02
Hugely successful image of the problem. Google shows it, and you know the question is the one you want to ask. — dEmigOd, Mar 08 '22 at 12:07

score 17 · Accepted Answer · answered May 13 '14 at 06:37

TikZ 3.0.0 provides a bending library for arrow tips placed on non-straight paths (see 16.3.8 Bending and Flexing on pgfmanual).

Loading the library makes flex=1 the default choice, but sometimes it worth to use custom values:

\documentclass[tikz,border=3pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,bending}

\begin{document}
\begin{tikzpicture}[>=stealth]
\draw[->] (0,0) arc (00:290:.15cm); % <= default flex=1
\end{tikzpicture}

\begin{tikzpicture}[>=stealth]
\draw[-{>[flex=0.75]}] (0,0) arc (00:290:.15cm); % <= custom flex, better output
\end{tikzpicture}

\end{document}

Output with flex=1:

enter image description here

Output with flex=0.75:

enter image description here

Notice that you can use this also in low-level pgf, as \pgfsetarrowsend{Latex[flex=0.75]} for example. Thanks — Rmano, Mar 07 '19 at 11:19

score 6 · Answer 2 · edited Jun 10 '20 at 12:32

You can add a small unseen straight line at the end - to correct the arrow direction. You can use the shorten option. Like this:

\documentclass{article}        
\usepackage{tikz}
\usetikzlibrary{arrows}
\begin{document}
\begin{tikzpicture}[>=stealth]
  \draw[->, shorten >=-1pt] (0,0) arc (00:290:.15cm);
\end{tikzpicture}
\end{document}

Arc with arrow

Edit: This answer was written before I knew about Bending and Flexing in the pgfmanual 16.3.8 that is specific for this purpose. See answer by @Claudio Fiandrino.

How can I improve the look of an arrowhead at the end of a small-radius arc?

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