# Bold, upright greek symbol, \bm not working

I seem to have a problem. My task is to transfer several scanned equations into TeX equations. Now my greek symbols won't accept to stay upright and italicized. \bm is somehow not working at all, \boldsymbol only making italicized version, \mathrm is powerless, \pmb only does italicized, I am starting to be at my wit's end and the internet seems to not help.

Code in TeXworks

\documentclass[a4paper,12pt,german]{article}

\usepackage{xcolor}
\usepackage{ngerman}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{bm}
\usepackage[OMLmathrm,OMLmathbf]{isomath}

\begin{document}

\section{Bild 1}
$$\bm{\kappa} \frac{\partial^2 T}{\partial x^2}=\frac{\partial T}{\partial t}$$

\end{document}

• You wrote, "my greek symbols won't ... stay upright and italicized". There seems to be a contradiction here: The symbols are either upright or they are italicized. They cannot be both at the same time. Please clarify your typesetting objective. – Mico Jun 29 '18 at 21:51
• Sorry, I messed up, it was late. I meant upright and bold. But I got helpful answers despite my mistake, thanks anyway! – LSCAD Jul 2 '18 at 11:28

The isomath package doesn't claim to make lowercase Greek letters upright and it doesn't.

If you want upright Greek lowercase, load upgreek:

\documentclass[a4paper,12pt]{article}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{xcolor}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{bm}
\usepackage{upgreek}
\usepackage[OMLmathrm,OMLmathbf]{isomath}

\begin{document}

\section{Bild 1}
$$\bm{\upkappa} \frac{\partial^2 T}{\partial x^2}=\frac{\partial T}{\partial t}$$

\end{document}


By the way, the ngerman package is obsolete and deprecated. Use babel instead.

• +1 for "the ngerman package is obsolete and deprecated". :-) – Mico Jun 29 '18 at 22:04

As an alternative to bm the isomath package defines its own \mathbold command:

\documentclass[a4paper,12pt,german]{article}

\usepackage{xcolor}
\usepackage{ngerman}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amssymb}

\usepackage[OMLmathrm,OMLmathbf]{isomath}
\usepackage{bm}
\begin{document}

\section{Bild 1}
$$\mathbold{\kappa}\kappa \frac{\partial^2 T}{\partial x^2}=\frac{\partial T}{\partial t}$$

\end{document}

• It wasn't exactly clear which font you wanted, \mathbold{\kappa} gives the bold version of \kappa which here is bold math italic rather than math italic, but you seemed to indicate you wanted upright? – David Carlisle Jun 29 '18 at 22:01

Since several other people have posted solutions using the same packages you were using, here is an alternative. I would personally recommend a modern toolchain with Unicode and OpenType math fonts whenever you aren't forced to use the legacy packages. Every single OpenType math font, including the default, comes with a more comprehensive selection of math symbols than is even possible with any combination of legacy packages, that match each other better and work out of the box with just the package unicode-math. This includes bold upright and bold italic Greek.

\documentclass[varwidth, preview, 12pt]{standalone}

\usepackage{polyglossia}
\usepackage{amsmath}
\usepackage[math-style=ISO]{unicode-math}
\usepackage{xcolor} % Not actually needed for this MWE.

\setmainlanguage{german}

\begin{document}

\section{Bild 1}

$$\symbfup{\kappa} \frac{\partial^2 T}{\partial x^2}=\frac{\partial T}{\partial t}$$

\end{document}


You might consider defining a semantic macro in case you want to migrate your source to a publisher with a different house style, or back-port to a different set of packages.

If you want to stick to legacy encodings, see section 2.2.1 of the isomath manual for various methods. Here is a version that loads the bold upright κ from GFS Artemisia:

\documentclass[varwidth, preview, 12pt]{standalone}

\usepackage[LGR, T1]{fontenc}
\usepackage{textcomp, amssymb} % Not used here.
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage{amsmath}
\usepackage[artemisia]{textgreek} % Or the font of your choice.

% This MWE does not require the other packages you included, but is compatible
% with them.

\newcommand{\mathbfup}[1]{\mathord{\textnormal{\textbf{#1}}}}

\begin{document}

\section{Bild 1}

$$\mathbfup{\textkappa} \frac{\partial^2 T}{\partial x^2}=\frac{\partial T}{\partial t}$$

\end{document}


Here is an alternative solution using only the same packages you loaded. The bold upright Greek font here is, by default, cbgreek.

\documentclass[varwidth, preview, 12pt]{standalone}

\usepackage[LGR, T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[greek, ngerman]{babel}
\usepackage{amsmath}

% This MWE does not require the other packages you included, but is compatible
% with them.

\newcommand{\greekbfup}[1]{\mathord{\text{\textgreek{\textbf{#1}}}}}

\begin{document}

\section{Bild 1}

$$\greekbfup{\textkappa} \frac{\partial^2 T}{\partial x^2}=\frac{\partial T}{\partial t}$$

\end{document}