article document class: remove boldface from all titles

Question

My question relates to remove boldface from chapter titles, section and subsection names on removing boldface from chapter titles, section and subsection names, the difference being that I need to remove boldface from chapter titles, section and subsection names from an article class document.

Answer 1

Here are two options:

1. sectsty:

   \documentclass{article}
   \usepackage{sectsty}% http://ctan.org/pkg/sectsty
   \allsectionsfont{\normalfont}
   \begin{document}
   \section{A section}
   \subsection{A subsection}
   \subsubsection{A subsubsection}
   \end{document}
   

   This provides a clean and understandable input. Another reference using this approach is available in Is it possible to change text color for all headings?

2. A patch of the section header printing macro \@sect using etoolbox:

   \documentclass{article}
   \usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
   \makeatletter
   \patchcmd{\@sect}% <cmd>
     {#6}% <search>
     {#6\normalfont}% <replace>
     {}{}% <success><failure>
   \makeatother
   \begin{document}
   \section{A section}
   \subsection{A subsection}
   \subsubsection{A subsubsection}
   \end{document}
   

   This is a little obscure. The sixth argument to \@sect stems from the same argument to \@startsection - the default section-producing macro in latex.ltx. For example, here's an extract for \section, which provides as argument six \normalfont\Large\bfseries:

   \newcommand\section{\@startsection {section}{1}{\z@}%
                                      {-3.5ex \@plus -1ex \@minus -.2ex}%
                                      {2.3ex \@plus.2ex}%
                                      {\normalfont\Large\bfseries}}
   

   The patch inserts \normalfont after every sixth argument, regardless of the section being produced.

Both options produce the output:

Answer 2

Here's a solution using the titlesec package

A complete MWE follows. The code is commented which should explain the details- let me know if you need further details.

\documentclass{article}

\usepackage{titlesec}   % customizing sections
\usepackage{lipsum}

% custom section
\titleformat{\section}
{\normalfont\Large}% format applied to label+text
{\thesection}% label
{5pt}% horizontal separation between label and title body
{}% before the title body
[]% after the title body

% custom subsection
\titleformat{\subsection}
{\normalfont\large}% format applied to label+text
{\thesubsection}% label
{5pt}% horizontal separation between label and title body
{}% before the title body
[]% after the title body

\begin{document}

\section{My section}
\lipsum[1]
\subsection{My subsection}
\lipsum[2]
\end{document}