# Why is the superscript math not bold? [duplicate]

I'm trying to get bold vectors in a superscript, but for some reason this won't happen when using the cmbright package (I like the font). Is there a way to get it to behave? Code:

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{cmbright}

\begin{document}

This is a bold vector
$$\mathbf{p}$$

This is a plane wave
$$\psi=Ae^{i(Et-\mathbf{p}\cdot\mathbf{x})}$$

\end{document}


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• It is actually bold. – Manuel Jan 17 at 23:28
• @Manuel nope:-) – David Carlisle Jan 17 at 23:29
• @DavidCarlisle I answered just by looking at the picture. And looking again I see it upright an a little darker than the x next to it... and now I see that the x is supposed to be bold too. – Manuel Jan 17 at 23:38

LaTeX does warn you

LaTeX Font Warning: Font shape OT1/cmbr/bx/n' in size <8> not available
(Font)              Font shape OT1/cmbr/m/n' tried instead on input line 9.

LaTeX Font Warning: Font shape OT1/cmbr/bx/n' in size <6> not available
(Font)              Font shape OT1/cmbr/m/n' tried instead on input line 9.


the maintainer of the package chose to do that, defining, in the fd file

\DeclareFontShape{OT1}{cmbr}{bx}{n}{%
<-9>sub*cmbr/m/n%
<9->cmbrbx10%
}{}


So if you go

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{cmbright}

\DeclareFontShape{OT1}{cmbr}{bx}{n}{%
<->cmbrbx10%
}{}

\begin{document}

This is a bold vector
$$\mathbf{p}$$

This is a plane wave
$$\psi=Ae^{i(Et-\mathbf{p}\cdot\mathbf{x})}$$

\end{document}


you would get bold at all sizes

• Thanks for the quick response! Works fine. Seems odd that they would choose to do this - is there a disadvantage to having small bold letters such as this? – Garf Jan 17 at 23:36
• @Garf Not really any disadvantage, especially now the fonts are available in type1 scalable form. Of course one might argue that at subscript sizes the designed 7pt or 5pt font should be more readable than a scaled down 10pt font, but for small runs of characters it seems fine to me and certainly it's more convenient to allow it but then not use bold in subsubscripts if it looks cramped than to disallow it at the font loading stage. – David Carlisle Jan 17 at 23:40