[Tex/LaTex] Bold \varnothing

Question

I'm using the symbol \varnothing and it turns out I could do with a bold version of it.

Any ideas?

Also, I'm using \phi as a 'lowercase' version of it, any improvements to this strategy would also be welcome.

Answer 1

We can use another method to bold Greek letters and symbols that \mathbf doesn't work on, but this method doesn't work on \varnothing. However, it does work on \O and \emptyset.

\pmb was the only one to work on \varnothing but as barbara beeton pointed out it doesn't look that great. If you are okay with using \O or \emptyset, we can avoid the use of \pmb

\documentclass{article}
\usepackage{mathtools}
\usepackage{amssymb}
\newcommand{\bfs}[1]{\mbox{\boldmath$#1$}}
\begin{document}
\begin{alignat*}{4}                                                                 
  \varnothing & \qquad\bfs{\varnothing} & \qquad \mathbf{\varnothing}               
  & \qquad \pmb{\varnothing}\\                                                      
  \phi & \qquad\bfs{\phi} & \qquad \mathbf{\phi} & \qquad \pmb{\phi}\\              
  \Phi & \qquad\bfs{\Phi} & \qquad \mathbf{\Phi} & \qquad \pmb{\Phi}\\              
  \O & \qquad\bfs{\O} & \qquad \mathbf{\O} & \qquad \pmb{\O}\\                      
  \emptyset & \qquad\bfs{\emptyset} & \qquad \mathbf{\emptyset}                     
  & \qquad \pmb{\emptyset}                                                          
\end{alignat*}
\end{document}

Close up of \pmb

Close up of \newcommand which didn't work on \varnothing but works on the rest.