Curly lower case 'k'

Question

I want a symbol that it is to $k$ as $\ell$ is to $l$.

I looked at Scott Pakin's comprehensive Symbol's list and used detexify but I have not found it.

EDIT: I found a solution but it is a commercial font: http://www.pctex.com/mtpro2.html#Features_of_MTPro2 the cript fonts look really nice :(

Answer 1

As mentioned in your edit, the full version of MTPro2 from PCTeX is non-free and chargeable but includes a wide range of fonts including a script font for use in mathmode that is easy to call:

\documentclass{article}
\usepackage[mtpscr]{mtpro2}
\begin{document}
$\mathscr{kl}$
\end{document}

produces:

Answer 2

Having exactly the same problem (in particular I was looking for a k which cannot be confused with a \kappa), I stumbled upon two interesting options, both of which are shown below. While Zapf Chancery (pzc) offers a nice mathcal-like font, I prefer the actual typeset of the k of the Antykwa Toruńska (antt)

\documentclass{scrartcl}
\DeclareMathAlphabet{\mathantt}{OT1}{antt}{li}{it}
\DeclareMathAlphabet{\mathpzc}{OT1}{pzc}{m}{it}

\begin{document}

$\mathantt{abcdefghijklmnopqrstuvwxyz}$

$\mathpzc{abcdefghijklmnopqrstuvwxyz}$

\end{document}