Why does the switch to ClearSans font fails in LuaLateX?

Question

At the moment I am experimenting with a sans-serif font for figures and a serif font for the rest of the document. When compiling this MWE with pdflatex everything seems to work smoothly. Switching to lualatex (on Texlive 2014) leads to error messages (Font shape OT1/ClearSans(0)/m/sl undefined) that some characters cannot be found and they are replaced by the standard serif font.

Why is the font handling different in this case and how can I fix this?

\documentclass{article}

\usepackage{pgfplots}

\usepackage{ClearSans}

\usepackage[eulergreek]{sansmath}

\pgfplotsset{
    tick label style = {font=\sansmath\sffamily},
    every axis label = {font=\sansmath\sffamily},
    legend style = {font=\sansmath\sffamily},
    label style = {font=\sansmath\sffamily},
    /tikz/font=\sansmath\sffamily
}

\begin{document}

\begin{figure}
    \begin{sansmath}
        \begin{tikzpicture}
                \begin{axis}
                        \addplot [blue] coordinates { (0,0) (1,2) };
                \end{axis}
                \node at (4, 1) { $\Delta T_{\mathrm S} + 25 + \alpha + \beta + a^2$};
                \node at (2, 5) {normal sans serif text};
        \end{tikzpicture} 
    \end{sansmath}
\caption{Some caption text.}
\end{figure}


text text text...

\begin{equation}
a^2 + b^2 = c^2
\end{equation}

\end{document}

"Why is the font handling different in this case and how can I fix this?" Tautological answer: because lualatex and pdflatex handle font in different ways. You can see http://tex.stackexchange.com/questions/13593/the-differences-between-tex-engines for some more details (not a dupe). [This comment is less relevant now that your title is complete, I'm afraid] — T. Verron, Jun 27 '14 at 14:27
@StephanLehmke: Thanks, that last bit got lost somehow before saving. — Alexander, Jun 27 '14 at 14:27
@egreg: That almost solves it, now the numbers are sans-serif but in italics. — Alexander, Jun 27 '14 at 14:34

egreg · Accepted Answer · 2014-06-27T14:52:48.240

The sansmath does

\providecommand\sansmathencoding{OT1}

at the beginning; this can so be overridden by adding

\newcommand\sansmathencoding{\encodingdefault}

before loading the package. You also must ensure that fontspec doesn't hijack math codes and fix another setting where sansmath hardwires OT1. For uppercase Greek, EULERGREEK is needed.

\documentclass{article}

\usepackage{pgfplots}
\usepackage[no-math]{fontspec}
\usepackage{ClearSans}

\newcommand{\sansmathencoding}{\encodingdefault}
\usepackage[EULERGREEK]{sansmath}
\SetSymbolFont{operators}{sans}{\encodingdefault}{\sfdefault}{m}{n}

\pgfplotsset{
    tick label style = {font=\sansmath\sffamily},
    every axis label = {font=\sansmath\sffamily},
    legend style = {font=\sansmath\sffamily},
    label style = {font=\sansmath\sffamily},
    /tikz/font=\sansmath\sffamily
}

\begin{document}

\begin{figure}
\centering
\begin{sansmath}
\begin{tikzpicture}
\begin{axis}
  \addplot [blue] coordinates { (0,0) (1,2) };
\end{axis}
\node at (4, 1) { $\Delta T_{\mathrm{S}} + 25 + \alpha + \beta + a^2$};
\node at (2, 5) {normal sans serif text};
\end{tikzpicture} 
\end{sansmath}
\caption{Some caption text with math $\Delta T_{\mathrm{S}} + 25 + \alpha + \beta + a^2$.}
\end{figure}


text text text...

\begin{equation}
a^2 + b^2 = c^2
\end{equation}

\end{document}

enter image description here

I really can't understand why graphs with sans serif type are so fashionable.

This is great, thank you. It is not so much fashion but more or less a universal style convention in many scientific journals. I have no strong feelings about the issue but when combining different graphs from other sources it is much nicer if they have common typesetting. — Alexander, Jun 27 '14 at 15:12
@Alexander Is it a convention? Or is it just that they include a figure which came from a different program so they cannot use (they don't know) the font used in the document? I always thought it was the second option. — Manuel, Jun 27 '14 at 15:31
@Manuel, egreg: Taken from the Authors guide for figures of Science: "Use a sans-serif font whenever possible (we prefer Helvetica)." — Alexander, Jun 27 '14 at 16:03

Why does the switch to ClearSans font fails in LuaLateX?

1 Answers1