Increase a bit the bold symbols in mtpro2

Supposing to have this simple MWE:

\documentclass[12pt]{article}
\usepackage{newtxtext}
\usepackage{mathtools}
\usepackage{mtpro2}

\begin{document}
Normal in line-mode without the bold: $[{}\dotsb{}]$

Bold in line mode: $\boldsymbol{[}{}\dotsb{}\boldsymbol{]}$.

Using a first formula without the bold and the second formula with the bold:

$$\varphi(\bar{r},t)=k_{e}q\Biggl[\frac{1}{\kappa_\mathbf{vuoto}}\Biggr],\qquad \bar{A}(\bar{r},t)=k_{e}qc^{2}\boldsymbol{\Biggl[}\frac{\bar{u}_{q}}{\kappa_{\mathbf{vuoto}}}\boldsymbol{\Biggr]}$$
\end{document}


You can see that there is not much difference between the large brackets without bold (first formula with equation) and with bold (second formula with equation).

Is it possible to increase a bit the bold square parenthesis?

N.B. I not can use the bm package because it generates a crash of my book using a lot of packages.

The complete version (but not the "lite" subset) of the mtpro2 package provides the switch \boldmath. It must be executed prior to entering math mode.

Is that bold enough for you?

\documentclass[12pt]{article}
\usepackage{mathtools,booktabs}
\usepackage{newtxtext,mtpro2}
\begin{document}
\begin{tabular}{@{}rl@{}}
\toprule
\verb+$[{}\dotsb{}]$+          &          $[{}\dotsb{}]$ \\
\verb+\boldmath$[{}\dotsb{}]$+ & \boldmath$[{}\dotsb{}]$ \\
\bottomrule
\end{tabular}
\end{document}

• Humily it seem the same using \boldsymbol 😩😩😩😩. But is it possible to increase it? I have thinked to use countour package or showtext but I not want to use other packages. Jul 18 at 14:40
• @Sebastiano - In addition to \boldmath, the mtpro2 package also provides the switch \heavymath. Unfortunately, \heavymath does not work on round parentheses and square brackets. For what it's worth, though, \heavymath does work on \sum and \int.
– Mico
Jul 18 at 18:00
• Hi Mico. I have improved my question and I have thought to use amsbsy package with the command \pmb: see this example $$\varphi(\bar{r},t)=k_{e}q\boldsymbol{\Biggl[}\frac{1}{\kappa_\mathbf{vuoto}}\boldsymbol{\Biggr]},\qquad \bar{A}(\bar{r},t)=k_{e}qc^{2}\boldsymbol{\pmb{\Biggl[}}\frac{\bar{u}_{q}}{\kappa_{\mathbf{vuoto}}}\boldsymbol{\pmb{\Biggr]}}$$. The result it is better and the bold is more evident. There is also contour package but some of the commands to have a uniform and symmetrical bold for me are unclear. Jul 24 at 22:14